Not a giant Tebow fan. I don't believe he is humble in that he openly flaunts his humility. I'm a die hard Mets fan.
He was not a good NFL QB. He had the opportunity to be a tight end and dismissed that.
All that being said, I don't see where the Mets getting a strong "character guy" is a stretch or a bad move. There is nothing to lose by having him playing in low-A ball for them. He will be surrounded by 18-21 year olds who can use a solid and upright accomplished athlete to set an example for them. He was signed for that reason mainly.
If, by chance, he excels to any degree, then that is all gravy.