You will get heat, but feel free to always express your opinion ^^ anyway...
As a DPS good damage indicates you are playing your job well or are on the right track at the very least, almost everything in the game as a Lv and Ilv requirement, so its doable at those levels, gearing up only makes it easier but if you can't pull your weight at minimum Ilv then you clearly aren't as good as you think, and if you STILL can't pull your weight after that then you are just bad...
But that's only a rough guess and not accurate at all, and is for sure not good enough for anything remotely challenging, especially progression raiding, you need numbers.
Yes your Basic rotations are easily spelled out for you, but how do you think people discovered the Optimal rotations everyone uses currently? they used a parser to more accurately calculate everything. A parser just saves time and makes it easier to see what the issue/who the issue is damage wise.
It's also rude, inconsiderate and plain snobby to just stroll into content and not perform on par with at least your expected minimum contribution, which is what people are angry about, if content is cleared then no one really cares if you could do better, but when you're holding back a group you deserve to be judged and removed if you aren't pulling your weight in anything above dungeon level content. STOP expecting us to carry people through content without them putting in effort to learn anything. In this case the player isn't putting out enough DPS (because you obviously can't parse mechanics), it's not our responsibility to teach them how to play their Job in the instance. If they can't meet the DPS check at the minimum Ilv or later it's not worth the rest of the player's time in keeping them to wipe over and over. If the problem is the mechanic's of the fight i'll give them a few tries at most, but after that it's clear they won't get it and we need to replace them to have a hope of passing the content.
The only time a "group meeting" would even work is for a pre-made group, randoms are too impatience and prone to rage quitting to bother with that, plus the major issue of language barriersif i physically can't explain it to them then i'll have no choice but to quit, or replace them. And i sure as hell won't eat a lock out if its only one person causing the issue that we could just replace.