Obviously it's easy to second guess a draft after the fact. But going into this year's draft, many thought the Cardinals should target an offensive tackle early. Due to the Kevin Kolb trade, Arizona was without a second-round pick this year. That meant if they wanted a good tackle, the first round would have been the place for one.
Although Brown isn't one of the better left tackles in the NFL, it's still a big blow to the Cardinals. Arizona's offensive line was already a weakness with Brown. Without him, its' a downright disaster. Arizona could have remedied its line in April and maybe should have.
Offensive tackle Riley Reiff was still available when the Cardinals picked. It's likely he would have been an immediate starter for the Cardinals, on either side of the line. Although the Lions are slowly working Reiff into the lineup, he has looked good in the preseason. He's still coming along in pass protection, but he's an aggressive run blocker.
Cardinals offensive line coach Russ Grimm has worked miracles in the past. But in Arizona, he just doesn't have the pieces with which to work. Because of that, whomever plays quarterback for the Cardinals may not be upright long enough to get Floyd the ball.