while the democracies that appoint the ECB
  think it is going too far.

Often in politics you want someone to feel threatened, but you don't want to look like an asshole by threatening them yourself.

I'm sure France and Germany can put up the money to cover profligate Greek public spending if they want to. But if they've decided Greece needs to be cut off, I'm sure they'd much rather have an anonymous non-german non-french bureaucrat deliver the bad news than do it themselves.