A fairly large amount (though still outweighed by other issues) was just outright stolen as well. Not many Greeks were too surprised to discover corruption, but the amounts have surprised many people. I think it was widely believed that officials were pocketing "modest" amounts of money (€100k here, €150k there), but some turned out to have been pocketing Swiss-bank-account sized amounts of money, tens of millions. A number of the arms deals appear to have been corrupted as well, e.g. both Russia's Almaz-Antey, and Germany's Rheinmetall, appear to have paid large amounts in bribes, presumably to divert even larger amounts of contracts. And the Olympics construction contracts were almost certainly not clean.

One thing that gained Syriza some centrist votes is that they come across as at least having clean hands: good or bad policies, people believe they aren't caught up in clientelist networks and stealing millions personally. Whereas the previous ND/Pasok unity government was widely suspected of still trying to cover up skeletons in its closet (e.g. the scandal over trying to suppress the Lagarde list didn't improve its image).