Keep in mind the very best in the profession is .667 (Belichick). So the question is how far Fisher's .524 is from .667? Essentially 11-5 is what the very best coaches average (and with arguably the best qb of all time for 15 years), so that's the best anyone has proven in the modern NFL.
QB killer? McNair was effective for years. Vince Young (Mr. I need to rent a whole plane so I can fly alone) killed himself.
Belichick was 36-44 when he got to NE. Some of my friends would tell you that means he's a "f**king loser coach, not fit for waterboy at my high school", but look what happened after that. Marv was a "f**king loser coach" too when he got to Buffalo, his KC record was 31-42. Winning a championship with the JV Alouettes with 3 downs and a 55 yard line doesn't mean jack.
Rex's last couple years in NY not good enough? Give Belichick Geno Smith for a QB for 2 years and let's see what his record is.
I don't think it's really cronyism. Fisher has proven he can coach well in the NFL. The list of people walking the streets out there (who want to coach) who've proven likewise is very short.
Where has changing coaches every 3 years gotten the Bills?