Yep.
But to target a little closer, there are people who never look at Mids/MRB. There are people who do, but casually slot, and if they never complete there build, MEH it works and smashes things and they are happy. And then there are people who dont market, have some sort of farmer that may or may not afk, but really just dont care that much beyond some inf here and there.
For me, thats casuals. People that build out every build, twinked to max efficiency, definitely not a casual. Casuals (usually?) just dont care about 8/4. Feeling super matters more, and +1 or +2 to them with some random things they can smash around is good enough.
The comment that all HC players are casuals, I don't see that. There are definitely some NOT casuals that do some strange things, like limit player participation in groups because it doesnt maximize x y or z thing they are looking for.