Gabbert looked terrible last year but I wouldn't write him off yet. Wasn't he a Sophomore(RS) when he was drafted? I wouldn't write off any rookie QB drafted in the 1st round unless they're already like 25 or something. Even then they'd deserve a second season before being written off.
I don't know how I feel about him panning out but given the potential they saw in him, I'd give him 2 more seasons before you can really see what he's about. I don't expect a lot from a 1st year 21 year old QB. That doesn't mean they can't be good in their 1st season but I wouldn't expect it. Playing awful in year one doesn't mean a lot unless the coaches just think he's really dumb and will never get it.