MMORPGs generally don't tell you literally every little thing you need to do to maximize DPS. Part of the genres appeal is for people to figure it out for themselves, hence why guides and addons are even a thing. WoW in the last several years added a semi-guide to how to play your role and spec in the abilities/spell book. It's a decent start, but it doesn't help as much as people may think.
Truth be told, unless they're completely fresh to the idea of video games (which some people are), they'll have an idea of the fact there's a proper way to play. As surprising as it may be to some, even offline games have walkthrough and guides, which has been a thing for decades. In most cases, you don't need exact tellings or measurements, like with DPS meters, to perform decently at this point in the game... you really don't. Most of us will perform decently, at the very least, if we were to follow a guide or the help from people who do... or put 2 and 2 together when reading the tooltip. Of course, those meters would certainly be nice to figure out the rotation, but we already have a means for that obviously.
I'd wager the majority of people who don't even perform decently, are the folks who could not give less of a damn whether or not there were in-game means to learn. No amount of help, besides autoplaying the game for them, will change that attitude. Some would gladly quit before they're told how to play, since that involves taking time (even seconds) to read through text of something they do not care about. Those people are the ones you're probably referring to the most.
Nothing will change the way they choose to do things at this point... short of introducing something like the SSS as personal roadblocks to content. Even then though, expect a fair amount of players to pass that then halfass whatever it is they're doing. Laziness is a thing, even for the very best players out there. I would not be surprised however if even some of the "good" players begin frothing at the mouth in anger that the game is gating them by questioning their godliness lol.