Let's say Greek people bought tons of bitcoins, Then what? Price goes up, Chinese miners dumps lots of bitcoins & price gets even lower.
What will they do with those bitcoins? Will they eat "paper wallets" or "hard drives" that they hold bitcoins...
Nobody really knows what kind of effect this might have on the Euro or global economy, everyone is just speculating. Also if the Greeks go back to using Drachma, something like in Zimbabwe could happen.
Miners aren't your everyday Bitcoin user. They should know what they are doing and they aren't going to be dumping in huge sums.