The effusive praise over Zaire after one game is pretty goofy. Remember when Golson was a Heisman candidate after the first three games this year? Then the noise that goes along with being a D-I QB (soreness, new/varying defenses to study, school, etc.) set in and he more or less crumbled. It's not surprising that this happened, considering the unreasonable amount of the offensive load placed on Kelly's QB.
Off the top of my head, the best teams Kelly has coached were his last year at Cincinnati and ND in 2012. That year in Cincy he went back and forth between QBs (Tony Pike and some other guy) and in 2012 Rees was the reliever. Maybe that's not a coincidence.
I have no idea if statistics support this theory (and I'm sure, objectively, those weren't Kelly's best offensive seasons, but that doesn't always translate to a better, more effective team), and I never played football so I can't speak to the need to have one true leader at QB. But if there's anything that is certain after 5 years of Kelly, it's that his offense is not sustainable with just one guy under center. Shit, it might just not sustainable period, but maybe it is with a "1A" and a "1B"?