Well... NTR is supposed to hurt. As in YOU, the player are supposed to feel FOR the main character, to get upset, to get jealous on his behalf, to root for him. However counterintuitive to the plot that may seem.
You're supposed to get a... sad boner, if you will, when the person he holds so, so dear to him is even approached by another man, and a gut wrenching, puke inducing "reaction" with every step of her fall.
Make no mistake. NTR belongs to the masochistic genres of adult entertainment.
This whole "micro penis, premature eraculating, airhead looser" trope, that has you cheering for the other guy is NOT NTR at all. It's just easy to write, boooooring, cuckoldry.
It's for people that want to AVOID "feeling bad".
" i just think it's cool to appreciate kirito's character once in a while " - YES. That is indeed the right approach. The MC should be a good, decent, dependable man, that certainly does NOT deserve what he's getting. I wholeheartedly agree.
And Kirito does match that description.
So much so, in fact, that it's hard for people to even identify with him as an MC, and it breaks their immersion. Cannon wise...not Fujino game wise.
(enough ranting or i'll get my comment deleted again)