I was pretty impressed by what he did last year.
Brendan McKay was drafted 4th overall last year out of Louisville and hit .232/.349/.376 in low-A.
Adam Haseley was drafted 8th overall last year out of Virginia and hit .270/.350/.380 in low-A and .258/.315/.379 in A-ball.
Tim Tebow hit .226/.309/.347 in A-ball and high-A.
Tebow hadn't played in a dozen years since he was a junior in HS, the other two were highly celebrated college players from great programs who have been playing their entire lives. I'm no big fan of Tim Tebow, but it seems like he had a fairly impressive debut and given his athletic background you can't rule out that he could make major strides forward quickly.
Sure it's a publicity stunt and sure there's a 99% likelihood he'll never make it to the majors. But I don't think he's embarrassed himself, at all.