Miami wasnt willing to give him the control he wanted and will get at St Louis is what the talking heads are saying.
Always felt there is a % of people who vastly overrate Fisher and a % of people who vastly underrate him, and the truth is he's a pretty good coach. Probably had some teams underachieve and some teams overachieve. Rather have him than a lot of guys who keep getting jobs in the NFL, if I was a Rams fan.
He wants near-total control. You aren't going to get that at Miami. St. Louis has no reason not to give it.