It's not an issue of being emotionally scarred it's an issue of losing one's passion.
Again it's not the same as other closed Betas. It's a movement towards an entirely different computing model. One that not everyone accepts is valid (in fact I'd argue most don't think a completely browser based computing experience is valid at this point). So what Google needs more than anything is people who are passionate about that idea and who will strongly advocate for it.
So when people are rejected from the program I don't believe they'll cry but I do believe they'll feel less passionate about the idea as a whole.