Using a qr with discs require a certain amount of attention to detail and specifically reasonable eyesight to make the teeny tiny adjustment/positioning so that the rotor is lined up well, even with a well positioned caliper.
Some riders I know just aren't attentive or have an aptitude for mechanical stuff at all, so this is an issue.
but to be fair, it took me a while to get used to the mm dependant change of having to be careful of positioning , compared to an easy to eyeball rim wheel lining up, so I get the thru axle thing, even if I haven't used one ever.