The game slowly introduces various mechanics in different settings. People simply don't learn them, period. That's how you get players in ShB dungeons still running away with a stack. Largely, the playerbase ignores every learning opportunity the game throws around, and the community lets every learning opportunity slide because people just quickly want to be done with their duty. Or use the fig leaf of "the ToS is too draconic" as excuse. Especially mentors, who should be the ones speaking up precisely when not asked. The people who are asking question or want advice are the same people that could also look up the answers on their own. It is very much the ones that don't who need to be engaged with actively.

If you look at logs for on content Alliance raids, you will often see people with uptime in the range of 60-70%. This isn't a "wrong rotation" issue, or "my class wasn't explained". People are legit afk for a third of the fight. In a combat game. No amount of tutorial, difficulty wall, explanation or anything, will overcome people's unwillingness to actually play the game that they pay for and sink thousands of hours into.