Richard your posts are usually decent and warrant discussion and debate but what even is this? If this is a continuation from one of the other threads you started or participated in, shouldn't it go into those and contribute instead of further clogging up the forums and giving yourself another soapbox?

That being said, the game's leveling experience does teach you the basics of what's required to function at max level with the exception of PotD which neuters any and all lessons on team composition and play (positionals, tanks pull, stick together, etc). Every dungeon has mechanics that will be used later and the player is advised when they learn/can learn a new ability. Now the matter I believe you're addressing is that bad players will ignore these notifications and repeated lessons. Sadly that's on the individual unless the game delves into levels of handholding that I'm sure very few of us want.

The state of the game is hardly as bad as your theoretical situation and places a lot of the responsibility on the player to find the ways and means to improve themselves, just like most any game of any merit.