For two reasons...
the one thing that's missing for this defence (well, the most pressing need) is turnovers. Aside from porter and allen from time to time, there's no one on this defence who make game-breaking plays. Rashad is a speedster with a very good head on his shoulder, and he has that knack for the ball. Some might think he's 2nd round material but when it's all said and done, he'll be a first rounder in april i'm pretty sure. Great if he slips to us in the 2nd but i don't think so...
while i liked the sintim pick... the overrall upgrade on the defensive side of the ball is bigger with that playmaking safety than a pass rusher. Roth and anderson are picking up the OLB gig and they are improving slowly, but they are. Roth has one more year on his contract, so there is no immediate need to draft a guy (you usually draft first rounders who will contribute right off the bat) at that position
That's why i see more a guy like larry english in the second, who's coming from a small school and would have a whole season to learn the position while roth is filling the spot... he would be a nice rotational player and a special teamer in his first year.
that's mainly why i predict a R.Johnson / L.English combo but there could be other names in that 2a pick... guys like Herzlich :D (but he won't declare...
and i'd rather see him at ILB, but that's just me)