While I agree with a lot of your post, this point is significantly less important than it was pre-Firelands, due to the dungeon journal.
Prior to that you literally had no idea of the mechanics and needed a video for everything, now the video just lets you know how to handle it. Not saying it doesn't still help, just it's not nearly as important as it used to be.
On average sure, but there are definitely SOME amazing players who don't have the time to raid at that level.
The rest of your post is pretty much correct.