It's not because of the genjutsu controll, but due to CT, ain't it obvious?
Denial of what, exactly? Obito had perfect controll over 6 jins like 150 chapters ago. I'm not downrating the feat, I'm just saying it's not that impressive to be called an amazing feat with his current power. Sadly you fapboys wank over every single insignificant feat of Sasuke, which makes it a shame to say I like Sasuke in public - there is a risk I'd become associated with the guys like you if I do so, and that is certainly not something one could want.
He doesn't need to react, he can stay untouchable while using his kamui shurikens, for example. The point is that it can go either way, and if you
did read the whole thread, it all started with one of your fellows typing a mindless post of "genjutsu gg". That's what's become the reason of the whole discussion, obviously nobody here believes for real that Kakashi in the manga can defeat the current Sasuke. Well, at least those who have brain don't.
Probably you should've read the discussion you've wedged as well before doing so? Might've saved us some time here, and prevent you looking stupid.
Well,
fanfiction Kakashi (and I remind you again, as you probably will forget it, that the topic is him, not the one in the manga) can be constantly intangible. This way, as I explained above, he doesn't need to react.