The move to the ACC really hurt Pitt the most as they were living off of NY area recruiting and that dried up once they moved to the ACC as they almost never play a game within 200 miles of NYC anymore. Plus, they have made poor coaching hires. I do think Dixon saw the handwriting on the wall which prompted him to leave for TCU.
BC basketball is a challenging job and would have been in the BE and not playing many teams in the Northeast has hurt them. And, they pushed out Al Skinner and they have never recovered. Like Pitt, they have made some bad coaching hires. It seems they just don't care that much about basketball.
Syracuse won't ever sink to the levels of Pitt or BC. Why? There is a large fanbase that loves basketball. In the short term the Boeheim issue is negatively impacting performance, but it should be drawing to a close in the near future. He has done so much for Syracuse basketball that he does deserve to leave when he thinks it's time. That said, leaving the BE (and the BE Tournament) has impacted Syracuse basketball as Syracuse will not be a top 2 school in the ACC like they were in the BE, but Syracuse will still have the ability to compete for National Championships. Bottom line, the key to success for Syracuse will be the next coaching hire.