Yes it does make sense. Greeks are livid about EU micromanagement forcing Austerity against EU membership. That means it is international in nature. Greeks see other nations meddling with their business, plus, and more the case I can imagine, is disgust with their own corrupt leadership.
Even if the EU hadn't pushed austerity the riots would have happened, because it's more about no jobs and no income, the EU is just an excuse, in the same way the UK riots had their excuse in a shooting of a villain.