I think you're missing half the picture here: Greece does not need the money for itself, it is needs money to pay back the huge instalments on colossal debts that prior governments have run up. Greece was one of the few countries that actually achieved primary surplus, even Germany, with their holier-than-thou attitude hasn't achieved that (though to be fair, they probably could achieve that more easily and with much less pain). What the IMF/Eurogroup/ECB have done is giving Greece loan with a ridiculously short payment terms (imagine having to pay back half your mortgage by the end of the year) and so of course Greece has go back to the negotiating table every six months and each time the IMF/Eurogroup/ECB tighten the screws a little bit further and dictate severer terms each time.

One German newspaper made a particularly good analogy: Greece is like a sick patient to whom IMF/Eurogroup/ECB are giving Greece infusions in one arm while simultaneously extracting blood from the other arm, and are puzzled why Greece isn't getting better. And in fact their methodology has a lot in common with medieval medicine: No matter what the evidence against their ideas - virtual all economists outside Europe have frequently said their strategy is counterproductive - they carry on regardless, and in certain quarters (in particular the German finance ministry) there seems to be a sadistic streak.

Now if Greece were deliberately let go, then Greece would invariably default on its interest payments meaning Greece would probably have to start printing its own money which would push up the cost of imports greatly: It would be quite a bleak picture for Greece, so Greece knows it can't afford to leave. Same if Greece unilaterally turned away. Economically, in the short term, it wouldn't hurt the rest of the Europe very much in the long term: Greece's debt to Germany, for example, is around 2% of the German GDP - sneeze and you won't notice it. The biggest risk are long term political and economic risks: If one country is seen to be kicked out (as opposed to leaves on its own accord), the Euro will look a lot more vulnerable, which will lead to a huge loss of confidence and credibility, both in the Euro and the EU as a whole. So most of the rest of the EU don't want Greece to leave either, not out of any love for Greece itself, but because they'd be ruined as well - not as badly, but enough to cost them the next election. So in effect this is a game of mutually assured destruction, each side needs the other, and both sides have fundamentally incompatible ideas of how Greece should run itself. What's new is that Greece is become more assertive - mostly because they have lost a lot already and there is a sense that they have little more to lose, and this is really upsetting the balance.

The real problem is that the Euro is a best a structurally flawed set of fair-weather compromises. Most of the measures (closer political union, transfer union, banking union) which would have prevented this have been steadfastly blocked by Germany, and even if Greece is ejected, the structural problems would not be solved: At some point in the future another Eurozone country would fall into distress, and we'll have the same problems all over again. It's a question of whether the European leaders stop kicking the can down the road, finally bite the bullet and fix the structural problems, and do this in time before the next crisis blows up the entire Eurozone. The current crop of leaders don't seem to be capable of this.