I really don't think there was (or is) a magic bullet out there to address all this team's needs in a single offseason. What I saw last year was a team with little talent on the offensive and defensive line, unable to get a push or stop other teams when it mattered. Blowing our wad on a single player when we have, it appears to me, 2 or 3 holes on the offensive line, and 3 holes on the defensive line, to fill, doesn't seem like a good long-term strategy.
Before you ask, yes, I'm pretty much resigned to another bad year next year. I just don't think it's worth stressing over too much.