Comparing government to a household is not very helpful.
WTF?
Are you saying that Greece after the financial crisis is able to sustain the same level of debt that they were able to before the crisis?
I am saying that they have lower revenues after the crisis and therefore their ability to sustain a debt is similarly lowered. That means that what constituted a sustainable debt level in the past isn't relevant to what constitutes a sustainable debt level today. Why do you feel that's wrong?
When it comes to borrowing, governments and households are very different things. Nation states do not have to plan for eventual retirement or death; they are immortal entities whose long term income prospects (even for poor nations) are excellent - even poor countries tend to get wealthier over the long term.
The Greek situation has more in common with a bank run than it does with a household debt default. The banks don't have enough money to give all their depositors their money today. This is not a problem, as long as the depositors don't all simultaneously lose confidence in the bank's ability to ever give them their money.
In the event of a bank run, the solution is for the central bank, or other entities set up for the purpose, to lend lots of money (often on very generous terms) to prop up the bank until confidence returns.
The troika are the central bank in this analogy (and in the case of the ECB, quite literally). They can lend on generous terms (by which I mean long term loans at reasonable rates of interest, rather than the more usual - for nation states - short term loans at lower rates), and keep Greece afloat; or they can refuse to do so, and allow Greece to collapse, causing massive and needless hardship - which is basically what they have done.
This stupid and short sighted policy from the troika is basically the 'writ large' result of the cognitive error that sees national economies as sufficiently similar to household budgets as to be treated in the same way. It is a very, very stupid and harmful analogy - but it is very popular, because most people are morons, and have no understanding of economics beyond budgeting for their own households.
"I would understand this, if only it were far more simple than it really is", they cry. "So I shall pretend it's simple, and clamour for simple solutions, based on simple mindedness!"
If you can't see how that would lead to disaster, you are not alone.