And I struggle to believe that this accounts for half of people's encounters as suggested by OP. I acknowledge this exists (because I've encountered it), but I struggle to believe it's as big as made out. But yes, when they do it, it's wrong and a bad attitude and I have called people out who do this.
And in the 8 years I've been playing and offering my help, it's a small percentage of people who have chastised in return or refused to listen. And also not near half the DF groups I go in are 'bad' runs. Some don't know mechanics, particularly those who're new, but I found if I just explain the bits people are more likely to get wrong in the fights where mechanics are less obvious, I get more successes first pull than failures, indicating that people do listen.
But there's an attitude I've found throughout my time in playing MMO's that basically is "noobs don't listen and they'll always be terrible", but I tend to find it's the minority. And to some people, putting others down IS them trying to help and then said people wonder why people don't listen, which let's face it people don't tend to respond to that. I also find people have varying levels of what they consider acceptable performance, you'll see it on these forums too. OP's attitude if anything comes across less of a case of people who "refuse" but people who don't meet certain expectations.
And as a healer main, watching the complaints people have about healers, the most common one is about healers who refuse to heal and just DPS. Knowing how you practice and improve as a healer and with there being a DPS expectation, I end up taking the claim people are refusing with a pinch of salt, unless the person actively has said "I refuse to heal, I need my DPS bro". I replied to one such post earlier, so I'll just link my response to show what I mean than repeat it here.
https://forum.square-enix.com/ffxiv/...=1#post5548324
I don't get how OP is what the community made them and somehow I've not developed the same apparent disdain. Whilst to a degree I could think "maybe OP is just THAT unlucky" but I've read their attitude about other players, I am more convinced maybe it's a case of "a little from column A & a little from column B"