Classic IO scores are like credit scores: They do have some use in filtering people, but you can't opt out of them and you will be judged by them, and they don't account for individual circumstances.

(Slightly miffed ret paladin here who struggles to get into anything above a 12+ and who has seen groups at 9 and 10+ ask for 1000 IO score minimum, and yes, I am trying to 'get gud' through practice and research. Very much in that feels of 'Need IO score to get into higher keys...to get higher IO score. Currently at 931.7 IO score overall) via /r/wow https://ift.tt/3nuzJKB