This is such a weird issue to me.
I love playing competitively as immersion allows me and I love being on console and on my controller. If brehs are using Kb/M, fukk it, let them use it. I mean, I understand that it allows pin point accuracy but it's like playing against much younger competition with crazy fast twitch reflex compared to you.
If the gameplay is essentially -
In 3 seconds both opponents walk into the same room and try to shoot the other before being shot...GO - then, I can understand the complaints.
But most games are going to have competition that can aim better than you, react faster than you, but brehs really underrate tactics and strategy.
Sidenote: There is something about being as good as I can with a controller knowing it's the least advantaged option. It's not like it's a regression from what most people are used too, it's just not the option that allows you to treat Rainbow Six Siege like an excel spreadsheet that you're trying to change the box in the middle of the screen as quick as you can.