Given I was not referring to your one case but people in general, it makes me concerned that this 80% was actually just a bad Puppets Bunker run you had a poor experience with and tied in with other bad content runs you've had to come up with a really hyperbolic statement.
And my posts have been about people in general.
There can be multiple explanations as to why a healer hasn't done what you expect them to do in a given situation. Me? When I have party member do that, I talk to them. And I find that I get a huge mix of people. I get those who made an error in judgement, those who weren't thinking straight, those who thought they did the right thing or what was expected, that somebody else was on it, that they didn't notice something, that they tunnel visioned, that they are new and still learning, that they panicked, and most of the time I find people are responsive.
But I also get people who say that they don't care, that I don't pay their sub, that I shouldn't tell them how to do their job, ignore me, call me a bad name and so on. And cases where they seem to listen but don't improve.
So I am curious how you've ascertained in your huge percentage of cases that it was a toxic person who wants to only green DPS.
To draw a couple of example: a tank let me die in Titania yesterday, he went to DPS instead of take Puck off of me. I died, the other healer died. We wiped. I told the tank he should have been tanking Puck instead of focusing DPS. He simple said "I thought the other tank had it". Second pull, we complete it no problems.
The other example, I've had a tank before where they did do any of their tank mechanics, I tried to explain this to them and they told me I don't pay their sub and started to get abusive, we kicked and replaced him.
Both cases the tank did not do their job. Both cases we got wipes. One made an error in judgement, the other was an idiot with a crappy attitude. Both had different outcomes, one learned, one refused to.
Given one of the roles of a healer in this game is to green DPS, which is in this game's design. Is it not reasonable that in your army of people who green DPS that maybe not as many you think are bad or are toxic healers but people trying to do their job but are susceptible to human error?
Because I tend to find most healers aren't that bad. Given your use of hyperbole and you making assumptions, I feel it's likely that what's flawed here is your assessment on those healers you've had.