So you get a pass because you personally don't have it installed even though you're more than willing to ask for the information from someone else and use it to your advantage? Yeah that goes over about as well as a crooked politician trying to get out of a murder charge because HE didn't pull the trigger...it was the assassin he paid that pulled the trigger. GTFO.
You're missing the point entirely.
Also, most people don't like or appreciate getting called out when they're doing something wrong, and the person calling them out therefore looks like an ass to them. Well, as @
Granyala already said, the truth hurts sometimes. I personally would rather come across as a little bit of an ass for pointing out how someone is "doing it wrong" and provide some feedback than suffer through a dungeon or raid with someone either deliberately or inadvertently not doing their job and making the whole situation worse for everyone involved. If the person is willing to listen to criticism and improve their performance it's win win, if they're an ass about it and refuse to improve then it's lose lose...but in that situation I'd usually kick them. But for me their performance has to be REALLY bad for me to take it that far.
As I've said before, along with many others (someone even has a quote about it), yeah you pay your sub...but so do the other people in the group/ raid which means there's always AT LEAST 3 more people who pay a sub alongside you, which means you're in the minority. Playing sub optimally on purpose is disrespectful to everyone else in the group, and being unwilling to change your playstyle to be more effective and/or helpful to the group or raid is just as disrespectful.