Here's what you aren't getting. You are comparing the same place in the process while obviously stating they are in 2 separate spots.
In time, once this system and culture is fully established, maybe we end up drafting our future Brady and future Gronk, and can be in the same spot. But yes, we aren't there yet. What seems to be lost on you is that by holding onto guys who resist the culture and don't buy in just because they are immensely talented, it can not only hold back the process, but prevent it from ever really coalescing, in which case you end up with a divided locker room, with which it is incredibly hard to win a Superbowl with.
Ultimately, what will determine whether the process they are in works is Pace's draft picks. No question on that at all.
But in the meantime, yes, we have a bit of a purge going, and those who don't fit for whatever reason will be let go. That doesn't mean everyone will be gone (although given how talent deficient the Bears have been before Pace, that's not out of the realm of possibility in the long run), but it does mean some good players who don't fit will be shown the door, and it will be incumbent on Pace to replace them in the draft.
And those rookies will be coming into a culture from day 1 that is rubber stamped by the GM and coaches, thus helping them adapt and adopt that culture as well.
Personally, I think its insane to treat this as a bad thing... provided the Bears can get the talent they need in the draft.