In Vinny's case it was twice & both times he was criticized for "not being too bright" although he cultivated a winning culture, led a young squad into the post-season & even won a series. But you are right in that there were rumors which indicated Vinny wasn't well liked by the players (both Bulls/Clips).

I guess Mark Jackson's case could best be compared to Lionel Hollins in that they both developed young cornerstone players (Conley/Gasol vs. Klay/Curry), cultivated a winning culture & were well liked by their players but clashed w/ management b/c of they didn't like anyone stepping into their den & telling them how to do their job. They basically felt disrespected & started ego tripping which cost them their job.

Kerr owes a lot of his early success to Mark Jackson just like Joerger owes his early career success to Hollins. Unlike recent hires such as Dwane Casey or Jeff Hornacek, they each had a steady foundation to build upon thus I feel like they would have to win a chip to insure long term job security. A good example would be Avery Johnson not getting the credit he deserved for taking the Mavs to the finals (although he won COY) b/c he inherited a perennial playoff team from Nelly. Then Carlisle inherits the team from Avery but didn't get his dues until the Mavs won a chip although he revived the Pistons (lol @ Larry Brown getting all the credit) plus won COY & could have made a Finals appearance w/ Indy if it wasn't for Prince chasing down Reggie in '04 & Artest being suspended for the '05 postseason (not to mention Jermaine O'Neal never being healthy for an entire postseason during Carlisle's tenure).

Steve Kerr is going to be under fire if the Warriors have a hiccup & get bounced in the 2nd round even if it is in part b/c of their main players being injured (Bogut/Lee). Recent history has shown ownership/upper management doesn't give 2 shyts unless the coach is bringing in the jewels.