Culley was probably not the "smartest" hire for a rebuild. The guy is 66 years old and had never even been a coordinator...unless you want to count 2 seasons as "passing game coordinator" with the ratbirds in 2019/2020. The hire made no sense in the first place, but, you give him ONE year and without a QB and a terrible roster? WTF, man?
It's an epidemic across the NFL where if you aren't winning by your second (maybe 3rd if you're lucky) season, regardless of the state of the roster, you're done. Chuck Noll was 12-30 in his first three years with the Stillers. Do they end up a dynasty in today's NFL? Bill Walsh was 2-14 and 6-10 his first two years in SF. Does he get that 3rd year (when they won a SB) today? Parcells was 3-12-1 in year one with the Giants. Does he get a second year? Ditka was 3-6 and 8-8. He get a 3rd year? Belichick went 5-11 his first year.
The list goes on. Teams nowadays have no patience to let a coach actually build a team and/or change a culture. You don't fix things post haste, regardless of the state of your roster, you're gone and they're on to the next schlub that they'll also replace in 2-3 years. It's insanity.