I don't dislike GSP. I feel like he should've stuck with his retiremwnt, though. He not only suffered career altering injuries while he was fighting, he also did after the retirement.
Say what you say about him, but he was fighting the best challengers available, and went through at least 2 generations of top WW.
No need to tarnish that, imo. And fighting Bisping would just be a weird move, especially for the belt.
But with less mobility and explosiveness, what are the odds of GSP returning and wrecking shit like he used to do in the early part of his career?
I think there are better odds of him having less ability and losing to guys he previously would have beaten.