The tax hikes greatly play into the angst of the people voting there in a direct indirect way.
Taxes like the VAT [which Greece hike significantly] have greatly lessened consumption, which tanks the economy. The tanked economy (lack of jobs, not affording to pay bills, etc) is what feeds the angst.
Instead of raising taxes and cutting government spending, they should cut the government spending (get rid of govt workers who are not needed, sell off state owned businesses, adjust pensions/retirement to reflect reality, etc) and also include tax incentives for growth.
I was reading an article on Greece yesterday and the pleas the (at the time last summer) new Greek Finance Minister was making on growth policies, in addition to cuts in spending, and how it fell on deaf ears in Berlin and Paris and elsewhere. I was astounded.
That would certainly be true here. Our left could care less about tax increases as they see it affecting someone else (rich), not them (whether that is true or not).
My comments were more directed toward attitude of free benefits rather than the tax side of austerity. From the practical side tax increases are irrelevant to austerity because at the current levels history shows us that total revenues tend to decrease as rates are increased due to tax avoidance and legal entity relocation.