Why would the other southern European countries want to be in the EU at this point? There's not much to gain, and they're likely to also be made an example of if another financial crisis strikes.
They just exercise some creativity by making sure they don't meet the requirements.
The main thing is that you can't tax by printing currency anymore which is a really easy way to levy taxes. That means you have to have an efficient taxation apparatus, tax the rich and poor equitably and be very careful with borrowing.
Greek's problem is that it isn't particularly strong in any of those and thus isn't really suited for being part of the Eurozone yet.
This I think is the main difference with the USA. The USA also has richer and poorer stats, but because of the shared language, history and culture, people in both the richer and the poorer states feel like a US citizen.
as the latter: Greece benefitted quite a bit from EU subsidies since joining. you can argue about if the same holds true for joining the eurozone.
> The terms of the deal for Greece have been pretty onerous, you lose control of your currency with no equivalent upside.
No upside? What do you call a decade of easy access to super cheap credit? Also, these terms are not unique to Greece, no other Euro-zone country has control over it's currency.
A poison pill. It's like giving free booze to an alcoholic. It's certainly not kindness.