See, I actually think Pace has played the Robinson thing pretty well. Once we got to the start of the season, it didn't really make much sense to commit long-term to Robinson. First, didn't have a long-term QB. If Mitch had started all season and put together 15 games like the last 5, then you'd have to either franchise him or sign him long-term. Even with 5 decent games there's still a decision to be made. Secondly, there's this whole pandemic thing. There is cap uncertainty in 2021 even now. Pace still doesn't know how much cap room he'll have next year. I think it was smart to not commit 18-20M to Robinson without even knowing if he'd have that much space and also saving space for a potential Trubisky extension (also there were escalators in Foles' contract).
As for Cohen, I also think that move makes sense. The primary focus in negotiations this offseason will be Robinson and now probably Trubisky. You risk losing Cohen if you focus on Robinson first in free agency. That could allow someone else to swoop in and take Cohen while you have him on the backburner. Plus, again without knowing the cap number, you don't want to sign ARob for 20M and then end up with only 2Mil in space and can't afford Cohen.
Now, I'm not trying to excuse Ryan Pace because he did sign Quinn, Trevathan, and Graham while the Bears were in the pandemic and also knowing he had Robinson and potentially Trubisky's contract situations coming up. But in March/April, maybe he thought it would be over and 2021 and beyond wouldn't be affected. So, if you buy that he is smart enough to plan for a lower cap, I think he did the right thing with Robinson.