Is he not an aging journeyman vet QB? Maybe 'aging' was a poor word to use as you took it extremely literal as in he's old. He's going on his 6th year in the league and has thrown 88 picks. Oh and he hardly played this year. The Saints opted to play Hill who is hardly a QB over him in the absence of Drew Brees. And he's about to be on his 3rd team in 3 years. Aging journeyman vet.
If Pace wants to go this route, he might as well just stick with Foles and not waste his time or cap space. Your ideal scenario of signing Winston is preposterous and as you conveniently ignored in my initial post is exactly the thing the Bears have done since Pace came it. It's not a winning formula.
No, what the Bears have mostly done the last dozen or so years is shit like the Watson hypothetical. Massive resource dumps into the likes of Jay Cutler or Mitchell Trubisky. Big trades for big talents that fall flat because the big talent never translate in Chicago. Then they're left with a substantial monetary, draft capital and perhaps most importantly playing time commitment to this one player. When these gambits fail they take the whole team down with them, whereas the Nick Foles or Mike Glennon shots in the dark have no real lasting consequences. Even if they dont pan out the Bears don't feel obligated to give those playing time to see what they have.
Meanwhile the Bears bring in Deshaun Watson, win four games, he pouts and whines like a petulant child yet still starts games because you have to start a guy who is taking up twenty-five percent of your cap and cost four draft picks and two good players to acquire.