Uhh why didn't we draft a QB? OR OL?

It's pretty obvious that our biggest weakness is our offensive line by a landslide.. What are we thinking drafting a WR? McCown looked awful tonight, and looks like he has no business as a starter in the NFL. Glennon is decent but really isn't a huge playmaker that can make a huge big impact alone. It was obvious watching Bortles that he was athletic and was going to be a solid NFL starter one day, and no one on the field for us has me thinking that..So what were we thinking drafting a WR? It's obvious, we needed a QB or a OL ? Mike Evans seems pretty disposable if we don't have someone who can get him the ball consistently or an offensive line that can keep the defense out of the QBs face....