Matt Yglesias has a good argument to the contrary:
On its face, the political crisis in Greece seems relatively likely to lead to Greece exiting the Eurozone. And why not? Europe’s leading politicians pretty clearly regret having let Greece in back in 1999 (particularly in off-the-record conversations), and Greek voters are clearly fed up with being told what to do by Brussels and Frankfurt. Journalistically, a “Grexit” is certainly the most interesting outcome, so people talk a lot about it, and at this point there are a lot of plausible theories about how it could go. But I think it’s not going to happen. The forces of the status quo will rally, and another grand coalition will lead Greece through several more dreary years of austerity and slow growth.
Nonetheless I think Germany wants them out. First, I think Germany regards Greece as a kind of cultural and economic cancer for the eurozone, and they don’t want to enshrine the principle that eighty percent default is OK. Second, Germany sees a fair amount of eurozone stability right now (NB: I’m not saying stability is always good in every way) and has noticed that the contagion effects from the recent Greek troubles have been small. This is not a bad time to get them out. Third, Germany is smart and knows that the real problems are Podemos in Spain and just about everyone in Italy and maybe even a few people (or more) in France. Now is a good time to send splinter parties a message that they had better not mess around with the Troika, and what could do that better than an economic disaster in a recalcitrant Greece?
So I think Germany will play brinksmanship with Syriza and, when the time comes, simply pull the plug and leave them high and dry.
Addendum: Here are some useful graphs.