If they aren't going to bother honoring the source material, why pay all that money for they intellectual property in the first place?
The reason that they pay for the intellectual property is because the public is already familiar with it, and they want to translate that familiarity into butts in seats.
We've seen this a thousand times before. If you don't show that you care about what fans like about the source material, this is what happens.
Non-fan: Hey, they made a movie about Panty Ninja Warrior. I heard of that before. I'll ask Ed. Ed knows all about that Panty Ninja Warrior stuff.
Fan: OMG it sucks! It's terrible! Her panties are supposed to be blue, not purple!
Non-fan: well, if that movie sucks, I will spend my hard-earned money on watching Fast and Furious 16: VW Beetles For Justice instead...
If a movie studio wants to buy an intellectual property to get more butts in seats, then great, but if they don't care enough to at least make a pass at pleasing the fans, then they're probably not competent enough nor passionate enough to make a good movie out of said property. Why spend the money on the rights to something if you're not going to put in a modicum of effort in doing what it takes to leverage that intellectual property into greater profits?
A good example of this is I, Robot. If they had just removed all references to Isaac Asimov, changed all the names, and called it an homage to Asimov instead of an adaptation of his work that used the title of one of his most famous stories, then what they would have had was just another fast, funny, and smart action movie typical of a Will Smith movie from that time. I would have been perfectly ok with it. But they had to put Asimov's name on it, and in my opinion, I had no choice but to judge the movie as an adaptation of the story I, Robot, and in that it falls miserably.