Has it though? While it's true that proceeds under TARP exceeded spendings, the government has had to hold those assets for years, and had to pay interest on its borrowings during that time. Those interest payments might well have exceeded the profits of the asset sales.
Also, even if it had to pay a little bit when adjusted for the cost of borrowing it's still a massive win. After all the government is nominally not a for-profit institution but rather an entity that helps their citizens (or at least tries to). But in this case it definitely turned out a lot better than one might have predicted at the time the program was launched.
In real terms, the Treasury should have recovered $467B 2014 dollars for its investment to have a 0% real rate of return. In fact, $25B real 2008 dollars were given to banks and never recovered.
Let me illustrate this with an example:
1. I borrow $1M at 5% p.a., for a year
2. I lend out this $1M to someone else at 7% p.a., for a year
3. A year passes
4. My debtor has not defaulted! Great, I collect my $1.07M
5. I pay back $1.05M
6. I am $20k ahead
TARP was a Treasury program, so wouldn't it have been financed by Treasury notes, which averaged about 2% during that period?