Lets be honest, the main focus of one button rotation is not for accessibility reasons , but i think they are testing the waters for more… accessible wow in other platforms. As i saw in many videos, there are classes that do 80-88% of their dps with one button (no cd’s).
So imagine having one button plus 5-6 keys for your cooldowns/interrupts/trinkets. Easier for a mobile screen and console controllers. And the main reason this happens is because they cannot grow their playerbase with the content they are producing.
You do know people have been using controllers to play WoW for quite a few expansions now?
It’s not ment for controller / console, it’s accessibility + ease of use.