I don't understand...

[Double]

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That does hold truth but OP's claim isn't that a player is afk or deliberately ruining runs, his claim is that he believes most people he run into isn't playing the way he wants them to.

He never said these players are preventing clears, he never stated that players are afk. His claim is that players aren't playing the way he wants them to which is subjective and undefined.
The best remedy is to simply play with people you would rather play with but quite honestly, no one likes pressure and no one welcomes expectancy when it's not needed.

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If you're running into people such as that, kindly offer advice. Most of the time, sane people will listen and take note for future reference. Unfortunately, most advice begins like this:

"BLM wtf use thunder."
"MNK wtf do you even know your rotation?"
"DRG do you even combo?"

"Scrub whm casting regen before pulls."(This is after the party member that knows better lets them keep doing it while the whm probably is unaware that you pull hate from regen on pulls).

This is the norm, this is our community and it sickens me to see this type of behavior become acceptable among ourselves.

You can just forget asking about a fight..