[army]

There's a difference between being enthusiastic about working for a company and being so keen to work to them that you're not even going to consider alternate offers. But seriously, you think that someone is going to be a bad employee just because your company isn't their one true love in the world?

I don't really think there's a justification for exploding offers that prevent people from considering alternatives, it's mainly just a way for employers to attempt to get the upper hand. From what I've seen it's often a) arrogant employers who can't comprehend that they're not the only attractive place to work b) game-playing employers who know that most college-age people aren't going to stand up to unreasonable demands and that these sort of gambits can prevent them from having to actually compete directly with other employers c) employers who do have an urgent need to fill a position (i.e. who aren't hiring an intern).