I don't think the argument is "be mediocre on both sides," but admit that you have to give your defense at least something to work with. It's not like we have the money to make "modest investments" on defensive holes if we're paying Hump, AQ, Drake, and figuring out the right tackle spot.
You fill up those salaries, add Hooper, and you're looking at, what, maybe $10 million left? To fill four starting and backup positions on the defense...? That's scary.
You're looking at hoping this team somehow develops so much offensive firepower with a new pass catching TE and, I dunno, a rookie WR, that we're going to just win shootouts. I don't see a team that has had success doing that in a while. Their defenses were at least something.