Nobody is saying Thibs isn't a good coach; many just disagree with just how great you think he is, that you think the players didn't get sick of him and instead were "turned" by the FO, and just how much of an impact he would have had this year. At their best he relied so much on Deng, Noah and Taj to anchor that defense, and now two of those guys are gone and one is an older, less effective version of himself. Again, Thibs is a better coach, but what would be so different this year? McDermott didn't play better under him (if he played at all). Rose was still maddeningly inconsistent. How would he have prevented Noah from inevitably falling apart? Or Dunleavy? About the only major difference that you could argue is maybe Mirotic wouldn't have stagnated since he seemed to improve throughout last season, so who knows if that would have continued under Thibs. The main problems are injuries, poor team construction and inconsistent players. I think those far outweigh the difference he'd bring over Hoiberg, and those are far more damning on the FO than firing a coach everyone was tired of playing for or working with.