Here's the thing. The truth is Rex is not NEARLY as good as Nunchucks paints him to be, or NEARLY as bad as Andy (and sometimes myself) would like to think. There are things he excels at and things that seem to be critical failings that have shown up over time, so we know them to be facts. Here is a balance sheet.
The Good
1. He is a superb communicator, especially with the media. He knows how to get his message across. When he first came to the Jets he made them instantly relevant and created the kind of excitement that boosted tickets sales and interest among the fans. He's done the same thing in Buffalo.
2. He is a superb defensive mind who proved he can stop good offenses both in Baltimore and NJ. What he did vs the Pats in 2010 AFCDG was Rex at his best. Granted it was only one game, and in the next 5 meetins the Pats scored 30+, but that was an unstoppable offense that was stopped in a big game. Maybe a better example are the 2 very close, low scoring losses last year with simply horrible defensive talent. Bottom line, the guy can coach defense.
3. He is a good motivator, especially in the short term (first couple of years)
4. He has the ability to take the heat off his team and put it squarely on himself
The Bad
1. He doesn't pay attention to the details - This is reflected mostly in his game management results, which are weak. You can literally count on his teams losing a TO they shouldn't or there being at least one substitution penalty, but it also shows in other aspects of his game. You'd think it would improve, but even after 6 years you kept seeing the same issues. So much so, that in the end, even Jet fans started to notice.
2. Players/coaches aren't held accountable you could see that issue throughout his entire run with the Jets. At its worst you got the debacle of a player walking off the field and the HC not knowing about a huge problem in his lockerroom. (2013 IIRC)
3. He doesn't know about coaching the offense. This one was the one I found most curious, because if you don't understand what makes offenses tick, you can't be as good a defensive coach as he is. You HAVE to know all about offensive theory to play good defense, yet he consistently coached some of the worst offenses in the league.for 6 years. basically I think he just gave to offense to the OC and lived with the results. I think this is what he's done with Roman, and I think it's lazy.
4. Not a good personnel guy. His drafts were routinely bad, for the most part. He wisely let others take the blame for them, but GM or not, Rex had a big hand in the results of Jets' drafts and they weren't good.
5. Long term Rex has proven he will eventually throw just about everybody under the bus to protect himself. That includes, players, coaches, and front office personnel. So while EVERYONE loves Rex at first, 3 or 4 years down the road, everyone starts to see the real Rex.
BOTTOM LINE: If you have a bad team and you need to put some energy into both the team and fan base, Rex would be a great hire. The problem is that Rex is a better builder than a maintainer (the hard joh), and over time all his warts will be revealed. In other words Rex is JUST what the Bills needed this year. They have a talented team, and Rex won't fu#ck that up, But if they think Rex is going to bring them long term success, they got the wrong guy. The fact is in 5 or 6 years the Bills will be looking for his replacement.