Somehow you've managed to miss the austere in austerity. The trait of great self-denial (especially refraining from worldly pleasures). Not only that, you've manage to ignore the role of income.
Income is a hard problem to control. Spending is an easy problem to control. If spending were the most important part of income, then Greece would have never gotten into trouble in the first place.
And "austerity" is not being used in the meaning above. It's painfully obvious that Greece isn't embracing any sort of self-denial, but is rather being subject to fiscal discipline by external pressure.