Idk about y'all but I didn't learn all that much about rotations/weaves/proper ogcds/ect until I hit ShB. Anything at SB and below, it never really mattered, you can play a bit suboptimally and still breeze through the content. I'd be willing to wager that most people have simply.. played the game without really *learning* the game, so even onto higher levels they think they're doing fine. I certainly did. All I knew was W2W and hitting my mits = good run, didn't think about rotation or other proper etiquette.

People refusing to do essential actions is a whole other matter, that is just people BMing the others lol