Why is doing things as fast as possible bad?

[Garlyle]

As a tank, I solve this problem easily. At the beginning of a dungeon... I ask. Ambiguity cleared up, problem solved, no more hate.

You're a good man, sir. (Or good woman, m'am; whichever you prefer)

You're also the exception, unfortunately. When I started healing level 50 content I was extremely uncomfortable with speedrunning and start panicking when a tank would proceed to pull everything with no announcement, especially when I knew straight up it was out of my capacity to heal them through. Hell, I've seen tanks straight up ignore it - I'd say "I can't heal enough to do full speedruns" and... they'd do it anyway, and then finally say something only when they inevitably died.

Speedrunning is something to be opted into, as it requires an extra level of comfort, knowledge, and execution from all involved. Treating it as a default state inevitably causes problems.

[Malzian]

That's great. Now get the other hundreds of speedrunners to do the same and this will no longer be an issue.

You're a good man, sir. (Or good woman, m'am; whichever you prefer)

You're also the exception, unfortunately.

Sir would be the word, and I wish I could do that. I can only speak for what I do, I even offer full and partial pulls for Speed runs. Sadly common courtesy isn't very common. However, if no one was ever the exception then there's no chance of it becoming the norm.