Well, maybe not just Sowell, but I'll use him as the scapegoat since he had the propensity to be a whiny *****. At any rate, if Snead had adequate protection this year, he'd be looking at being drafted in the Top 5 QBs, even considering that Bradford and Clausen will be entering this year. Factor in the 2010 rookie salary scale and Snead likely left a ton of money on the table this year. He can thank the OL for that.
Yes, I think an OL can make or break a QB.
ETA: And to answer your question of "where would he go?". I guess that depends on how well he did in the combine. If we start with this
list (only seniors) and add Bradford and Clausen, and toss in a wildcard (like a Mallet), he's not in the worst shape in the world. Certainly he would be drafted by Round 3 if he had a solid combine? Factor losing Hodge, McCluster, and a few o-lineman, and you could have a decent argument for Snead to press his luck. It's not going to get any easier next year.