I agree it should be one or another. IMO, the Bills should rebuild the team the right way. Trade players first and stockpile high draft picks. Rebuild for two to three years. Draft a QB high that has the potential to be an elite franchise QB. Next, start by building up both the offensive and defensive lines. If you look at successful teams like the Patriots and Raiders, both teams have solid pass protecting O-lines along with great QB's. Kyle Williams, Incognito and Wood are nearing the end of their careers, so you might as well try and get assets for them now. For players that have shorter playing careers such as RB's and DB's, I would wait to draft good one's until the team is close to being a playoff team. Otherwise I would have journeymen fill the positions until they can be replaced.
The point about continually drafting QB's is that the Bills don't intend on rebuilding (or "tanking"), so if they don't plan on giving up multiple first round picks (like Washington did for RGIII (three first round draft picks))), then they need to keep drafting QB's very frequently until one pans out.
I don't think they tanked either, but Sal C. thinks they did. I just think the team was poorly put together.