I wouldn't put it quite as harshly- but as a mother who's put her kid on solo flights since he was 12, I'd say he can handle it. Give him something to read, a decent supply of spending money and a phone card and then don't leave the airport till the Customer service people tell you it's in the air (not just pushed back from the gate). Then tell the kid that's what you'll do and where he can meet you if they cancel the flight.

I feel more sorry for the parents. I can't think of any comfortable, quiet places in EWR to wait outside of the secured area till the plane takes off.

Sometimes kids need exepriences like that under their belt to feel a little stronger and more competent- and they're less likely to panic if the accompanying parent doesn't act like it's a big deal.