I think what you are interpreting as bias is actually a set of conclusions reached by many members of this community following an epic multi-thread, more-than-a-year-long discussion of the George Zimmerman - Trayvon Martin case. Every scrap of information available to us was examined, challenged, tested, analyzed, poked, prodded, dissected, and debated for months. By the end of the Dying For Skittles thread and its offshoots, people had reached conclusions about the truth of certain claims. That is why you see people being very dismissive of things you haven't ever discussed with them.
I don't speak for the entire community but I think I can give you a general outline of how the discussions played out, and perhaps explain some of the current conversation.
And why would Trayvon be threatened by a man driving around IN a gated community? Obviously, he lives there and was able to get in with a vehicle. Maybe he's a pedophile looking to score a black boy with his blow gun or bare hands. If I were TM and walking back "home" at night in a gated community and noticed a car following me, driven by a "creepy ass cracker," I might walk around his car too and say "Get off me!" If he got out the car and dared question my presence there (profiling?), I might very well punch his ass (if I were young, dump, and full of you know what). And what's up with all the downplaying of the wounds on GZ? There were more than two wounds (more like 6 from the source I linked to) and a couple of witnesses who corroborated GZ's "beat down" story. And it was raining, so blood on the pavement could have washed away. That said, it is still plausible that GZ meant to detain the youth and got punched for it - and what a bone-headed maneuver that would have been. In either case, the guy deserved some punishment - which he got in the court of public opinion (e.g., death threats, hate mail)... and now more charges (back to the OP)
If you don't mind, I will address the points you raise one at a time.
And why would Trayvon be threatened by a man driving around IN a gated community?
I and several others have written about our own experiences of being followed by strangers. Those of us who've had that experience have no trouble understanding why Martin would have been worried, fearful, alarmed, and prepared to defend himself if it turned out that the guy from the car really was following him. We all understand why Martin would not have wanted lead the stranger to his home. No one wants a creepy stranger/stalker to know where they live. And we all understand why he would have called the guy stalking him a "creepy ass cracker". I call the guy who followed me creepy, and I would have called Zimmerman the same thing if he followed me, although I would have said "that creepy skinhead looking guy".
Many of us have also had the experience of seeing something that aroused our suspicions and calling 911 to report it. But no one here has said they made the choice to engage in armed pursuit, and the overwhelming majority say they would never make that choice, especially not after the 911 dispatcher said they didn't need us to do that. The general consensus here is that Zimmerman's action was dangerous, reckless, needlessly aggressive, and just the sort of thing that would cause the person being pursued to have a reasonable fear for his life and safety. So we tend to be dismissive of scenarios in which Zimmerman's actions are considered justified but Martin's fears are not.
If I were TM and walking back "home" at night in a gated community and noticed a car following me, driven by a "creepy ass cracker," I might walk around his car too and say "Get off me!" If he got out the car and dared question my presence there (profiling?), I might very well punch his ass (if I were young, dump, and full of you know what)
That claim Martin walked around Zimmerman's car comes from statements he made to the police that are impossible to reconcile with the recorded 911 call. It's not just a little discrepancy, either. It's a huge deviation from the chain of events reported by Zimmerman as they unfolded. I'm going to post some links you can follow to the recorded 911 call, Zimmerman's statements to Det. Serino later that night and in subsequent interviews, and the recorded walk through containing the bizarre claim that Martin walked around a corner between buildings, then came back to circle the car, and then walked back to the same corner and went between buildings, at which point Zimmerman got out of the car to check an address on a different street where Martin didn't go and Zimmerman wasn't going to stay.
https://www.youtube.com/watch?v=zj7qEcD8R-8
http://trayvon.axiomamnesia.com/audio/george-zimmermans-statements-sanford-pd-audio/
https://www.youtube.com/watch?v=X_2NeMrGCvg
It's going to take a while to listen to all of them, so you don't have to offer an opinion anytime soon. I just want you to know there was a lot of discussion of Zimmerman's statements to the police, and there is good reason to doubt parts of it. Anything that cannot be reconciled with the 911 call, time-wise and event-wise, and for which there is no other evidence, is simply not believable. Anything that even Zimmerman couldn't explain, and for which there is no other evidence, is also not believable. And I'm sure we all realize Zimmerman had every reason to cover his ass. He engaged in armed pursuit of an unarmed citizen who had every right to walk along that sidewalk unmolested, and the end result was a dead teenager. So for the most part, people here are very skeptical of Zimmerman's account. That's not anti-Zimmerman bias, it's the result of examining his claims and finding them unbelievable.
And what's up with all the downplaying of the wounds on GZ? There were more than two wounds (more like 6 from the source I linked to) and a couple of witnesses who corroborated GZ's "beat down" story. And it was raining, so blood on the pavement could have washed away.
That comes from reading the evidence the medic who examined him that night and the nurse who examined him the next day both saying the injuries were minor, and Zimmerman apparently agreed since he declined being examined by a doctor. There is a picture of him bleeding from tiny puncture wounds on the tip of his nose and from two very minor scrapes on his scalp. There are pictures of a small injury and swelling on the bridge of his nose. But there is no evidence of a "ground and pound" or of having his head bashed into a sidewalk. Various posters, including me, have compared his injuries to ones we have suffered and found them to be much less that our own minor injuries. For example, I once got a glancing blow on my forehead from a tree branch I was cutting with a chainsaw. I did not fall from my stepladder, I did not feel like I was going to die, I did not almost lose consciousness, but I did have a highly visible goose egg for the next several hours. I look at Zimmerman's pictures (
http://www.mynews13.com/content/dam/news/images/2012/05/GEORGE-ZIMMERMAN-BODY-0517.jpg) and watch the video of him walking into the Sanford Police Station that night (
http://abcnews.go.com/WNT/video/george-zimmerman-sanford-police-station-16416054) and I just don't see the same kind of swelling at the alleged point of impact. So I have doubts. I think Zimmerman was playing up the "danger" he was in so that the police would think he had reason to use deadly force on the unarmed teenager he pursued through a dark neighborhood.
That said, it is still plausible that GZ meant to detain the youth and got punched for it - and what a bone-headed maneuver that would have been. In either case, the guy deserved some punishment - which he got in the court of public opinion (e.g., death threats, hate mail)... and now more charges (back to the OP)
I agree with you the guy deserved some punishment, but I don't think death threats and hate mail are appropriate ones. I think he escaped an appropriate punishment because his legal team successfully race-baited the jury with tales of a black teenaged thug who attacked a poor, noble neighborhood watchman with a sidewalk.