This is not accurate.
We won our division last season with this roster AND one of the 3/4 worst coaching staffs in the league. There are some quality players on our roster. Really, the makings of a decent squad. The 'issue' with our roster isn't that it is crap, it is that it is unbalanced. And as much as I hated Tomlin we can't blame all of that on him. Most, but not all.
Someone else mentioned that the organization understood that Tomlin and Co couldn't develop a skill player if their lives depended on it. That is a major contributing factor to how our roster is so out of whack. Khan et al had to scrape together a group of older vets who were (are) seasons past their prime to be competitive. Then they overvalued certain players for whatever reason and presto we have a massively overpaid Watt, Heyward, and others.
I would absolutely trade Watt before I gave up on signing JPJ. The kid can play at a key position. Watt has faded badly each of the past two seasons which is a very real indicator that he's on his way downhill. Of course, we can argue whether he's been used correctly, the effectiveness of the defensive scheme, etc. Mr. Watt was the highest paid non-qb in the NFL last season. And that got us 11 sacks. 8th in the league.