Let me give a new player perspective as I just started a few weeks ago. (my own, not speaking for anyone)
Been a conjurer/white mage the entire time and haven't been contacted with positive or negative anything as of yet. Am trying this game out while on a Wow hiatus but not here because some annoying streamers or their fans showed up.
While you may find new players a bane on progression, here is what many of us are going through as we try to figure this game out from our new player brains, using our new player character in this new world of new rules, new mechanics and new expectations.
Many are like myself leveling on road to 70 servers and are just doing MSQ/class quests and no side content. Whatever hests, leves, roulette's are, we're not doing them yet. I'm doing the dungeons/raids or whatever that the MSQ makes me do and thus it's the first time I have been there and likely to fail non obvious mechanics the first time. We also won't be doing these dungeons again for a long time. I just made it through ARR post game slog and have a pile of expacs to catch up on. I am not going to remember that king moogle fight
For veteran players, you have done these dungeons/raids whatever dozens if not hundreds of times. It's not reasonable to expect new players to be close to that level because the Crystal tower may be old hat to you, but to us it's a forced raid we know nothing about. Expecting us to stop everything and read strats during leveling content is a silly demand.
From a new healers perspective? I do try to dps and heal and juggle that but I prioritize healing like 90 to 10 because I have seen tanks just melt so ridiculously fast and have to panic heal them. All the while looking at health bars and orange squares and circles. Now if I had done your dungeon a dozen or so more times, yeah. I would be more effective but expecting that out of the gate is unreasonable
The best thing to do is communicate with your team. Teamwork means more than "here to make your run smoother" You have to remember that Wow refugees are used to toxic runs where being new is worth being kicked for an overgeared replacement. You see a sprout, assume they are keeping quiet because being noticed tends to be negative. Even being generic with the strats can help "Remember, Dracula only bloodsucks of faze three which after he taunts us in bat form and we need to kill his werewolf minions except the grey wolf that's here to help us cause he's Han Velsing in disguise" Doesn't single anyone out and makes your runs smoother
Most of us new players will get better but if we are frustrated and feel unwelcome then we won't be around in the end which may be the goal of this thread in the end for all I know. Placing impediments on players to keep them out of content is an MMO killer. This game has a rep of players being kind to each other but this thread reads suspiciously like a git gud M+ Wow thread.