maybe it's as simple as some fans are just ready for a change? Sometimes getting some fresh blood and new energy in gives a program and fanbase a spark it could really use. Sometimes it doesn't work out at all of course... But that's a risk you take in order to potentially climb different heights.
Doing the same ol same ol, year after year is boring for some fans. It's nothing personal... Some of us are just eager to see someone else get a crack at it to see if maybe they could do better. We already know what Bronco does and can do.