I don't think people realize just how horrendous the Vikings o-line is. It's a snowball effect when the line is getting tooled consistently. Nobody has faced more pressured drop backs than Cousins, and he has a pretty good passer rating when pressured (5th among QBs with at least 400 dropbacks). It's not like he's holding onto the ball too long, his average time in the pocket is below league average. Vikes o-line has been an embarrassment for years now, and I don't think it's ever been worse.
To me, that falls on the GM. I don't know how many times they can draft receivers and corners so high, when the line needs to be top priority. All they've done is throw a couple very ill-advised contracts at Reiff and Remmers, and a stop-gap with Compton. Hell, spending a late second on O'Neill to start in his first year is their most commendable move, and he was supposed to be more of a development project. Not that he's been good, but at least they saw it as SOME sort of need...