According to this guy, people think BRF is too hard.
Also the item level gating is brickwalling potential raiders. Heroic BRF mechanics are obviously not challenging to most of us in GAF, but I need a whopping ilvl jump to hit the comfortable 670s to benchwarm for a 8/10H guild.
I watched the video, and while I don't feel like many of the specific observations are off base I'm struggling to come to the same conclusion as Preacher.
Is the situation realistically that BRF Mythic is beating people down? To answer that question I have to look at who that content is even relevant to. I'm on Sargeras, one of the most populated US Alliance servers and we have only 30 guilds who have downed one BRF Mythic boss, and fewer than twenty guilds with at least 2/10 progression into BRF. Frankly, I'm unconvinced that people are even attempting Mythic level content.
I would probably strongly disagree that Heroic BRF provides few mechanical hurdles for most of GAF. By and large I don't trust the community to be able to play their class well, and beyond that many players are often too lazy to even do the bare minimum leg work required for a deeper understanding of even personal mechanics. Resources for learning about class mechanics seem very limited to me. I can't really speak broadly but my guild is only 8/10 and we regularly carried low i-level potential recruits and were able to boost them from ~650 to 675+ (only to still seem the putting up woefully low numbers). Gear kind of rains down and Heroic content is still forgiving enough to allow for people to be carried, but I feel like player competency and understanding fight mechanics is more important than gear level even at the Heroic level. Gear pretty much rains down from the place.
It seems more like people aren't even getting to Mythic content, and Preacher's video focuses more on what's going on outside of raids than what's happening inside of them. Even for high end guilds I see them doing Heroic BRF and then going back to Mythic Highmaul. For just being what is ostensibly one tier the stairway to Mythic BRF is really long. Normal Highmaul. Heroic Highmaul. Heroic Blackrock Foundry. Potentially Mythic Highmaul, and then Mythic Blackrock Foundry. People that came in late might even insert LRF level raids into that.