Well, basically the EU forced harsh measures on Greece so Greece could get money from the EU to repay debts to banks and other institutional investors. Investors didn't loose anything (over simplifying here), the EU got it's money back and Greece, along with Greeks, paid the bill. Would have been easier to just wire the money over to the investors directly and leave the Greeks alone.

Investors understood the rescue of Greece exactly like that anyway if you ask me. But maybe the EU had to maintain the public impression of austerity. Or rather the Germans.