Frankly, the last paragraph is nonsense. We already know what the EU, basically in the same composition as now, does if a socialist government rejects a deal and it does not involve sweetening. The deal will get worse and still be take it or leave it. As far as I can see, the Greek negotiations are seen as a success. A lot of constitutional questions got solved in the interest of oligarchy and the left got hopelessly split by the question of the Greek Quisling government.
Though of couse it lead directly to the Brexit vote, but then you can't win them all.