So you basically didn't have any sort of counter argument so you're resorting to trolling/baiting. Got it.
As I said, BFA was chock full of systems that punished you for respeccing. Most of the BM Hunters were probably simply because at the time the effort it took to switch to MM wasn't perceived to be worth it by many Hunters. Given that the later, harder bosses are the ones that saw higher MM representation, this appears to be the case.
Besides, if your argument is that most Hunters are too stupid to comprehend anything beyond MM, maybe you should look beyond an expansion with borrowed power and scaling massively favouring BM. You would be very hard pressed to find many tiers in WoW's history where BM led MM on representation despite being worse in damage. You talk about the "trend being reversed" here as if the performance lead of MM in 8.1 was remotely comparable to that of BM in the later patches. Go look at tiers where MM actually led BM by a significant margin. In HFC, 6.2, nearly all raiding Hunters were playing MM. Same for Emerald Nightmare. Hell, why not just wait for raiding next week where you'll see MM leading BM in both M+ and raiding?