Does anyone know the objections to a long term postponement of debt payments?
As I understand it, it's twofold.
First, if the debts aren't repaid, then to some extent or another, taxpayers in other countries will end up paying more (as a result of their countries not getting some of the cash back). The concern is that those taxpayers will see that as unfair (not an unreasonable feeling for them). However, that's more of a political issue than an existential or economic one for the EU.
Second, if the EU/IMF/other creditors say yes to Greece's debt being written down, they'll face screams of "why not us too" from Portugal, Ireland and Spain - and their debts are orders of magnitude higher than Greece's. (And they went through the pain of austerity - and still are, without significant complaint). At worst, this leads to a far bigger economic crisis within the EU. At best, it significantly strengthens the hands of political parties in those countries (and elsewhere) who want an end to the EU.
The solution in Greece is pretty clear, in the isolated context of Greece, but it has big political ramifications in a wider context.
Could there be any greater conceit, than for someone to believe that the universe has to be simple enough for them to be able to understand it ?