I wont say that you're wrong, I just struggle to say defense bad, offense good while the parallels between the two units are vast. It's the same arguments for both sides of having really good stats, one dimensional units, weak in the trenches with and against the run, and took advantage of a weak schedule last season. Both units had some respectable showings against quality teams (2nd philly game, Detroit, LA), but also some total clunkers against quality teams (SF, Buffalo, GB).
It really just becomes the football version of the chicken or the egg argument. It starts to get into a different discussion but ultimately both units needed help this offseason if they are going to be top 5 in point differential once again this year as both units probably over achieved a season ago given their weaknesses.