"hey X, I've noticed you've been having troubles healing the tank with cure 1, cure 2 has a higher healing potency and is just marginally slower to cast and needs more MP than 1, plus, it's basically a straight up upgrade, and that'd make it easier to heal the tank

"
"hey X, I've noticed you've been standing around doing nothing during pulls and waiting to having to heal the tank, if you pop a regen on them and use your AoE spells on more than 2 mobs, you'd help the run immensely, holy is even a tank's best mitigation tool!

"
"hey Y, I've seen you're not using your mitigation skills during pulls or when you were on low health, abilities like rampart/30% mitigation/Reprisal+AL are helping a LOT against incoming damage and make it easier on the healer and are used best right after you pulled the enemies, not when they're almost dead!

"
"fuk u u don't pay my sub"
I'm not sure if this is something of a primal thing, but I've seen people, or have been insulted, for trying to help, no matter how nice it was
on the other hand, I've seen toxic players insult a "bad" player and that they should do X and Y, and said player then did X and Y without complaining a few times as well
but yeah, I wonder if you've played on a primal server before, seeing as most of the people that posted about seeing this were also on primal, if I'm not misremembering
"I bet the people trying to give the tips are doing in a tone that doesn't seem very pleasant."
see above, I've seen more nice people explaining abilities or mechanics get insulted by the players they're trying to help than actual a**holes being called what they are for, well, being a**holes