Hahahahahaha
No they don't. The sheer amount of people who have no idea what their rotation is can be staggering. Granted, it isn't entirely their fault when this game does absolutely nothing to teach.
Explain how WoW and other games have managed. It's called a scaling difficulty. You make content harder gradually, thus encouraging people to use more of their abilities. Trash can help people become aware of their surroundings, manage their CDs and heals better and know when to focus on particular targets. Higher floors of PotD exemplify this. And wouldn't you know, Yoshida himself acknowledged higher floors are very popular. When I can literally ignore every single boss mechanic in Kugane Castle, that reinforces bad habits. Such is why you'll often find someone who jump potion'd far more willing to accept advice than someone who's played the game for a year, albeit poorly. The latter had been doing things a certain why but only at say, Shinryu EX did they all stop working. Therefore, it has to be the game's fault not his. A lot of people think this way.The issue is playing it in Savage, which is the least fun content this game has made. To make leveling train for that, you'd make the game unfun; you'd have to bulk up the boss length and difficulty, because trash teaches you nothing about fifteen minute boss fights with one shots and enrage. The fact you have to almost always use a video walkthrough of the encounter after the first few days shows its not the job, its the mechanics.
And I think you need to stop assuming what other people think. Per your own example, nothing like PotD priority mobs exist in dungeons. It's among the reason people find them so repetitive. Put stuff like you see from floor 120 up and dungeon may finally have some life breathed into them. Every single one has been reduced to pulling until the game forces you to stop and AoEing things down. Likewise, they aren't. Susano EX requires very little awareness beyond the basic "don't stand here" mechanics. There's a reason Shinryu parties are a mess. He actually demands you pay attention, especially in phase one. People went from a general faceroll in Susano and Lakshmi to Shinryu with comparable expectations and got slaughtered.
Because you find something hard doesn't make it hard. It simply means you may lack experience.