You seem to be the one who isn't understanding the context of the posting.
He was replying to a user talking about why developers don't support online play between consoles and PC's, and he simply stated that in shooters, the keyboard mouse combo is better than a controller so it wouldn't work. He later added that in most other multiplatform genre's it doesn't really make a competitive difference which input method you use.
He didn't say you can't prefer one or the other, or that you wouldn't be better with one or the other personally. It was simply a generalized statement about PVP gaming, and how in genres other than shooters, the input method when put in the hands of a capable gamer won't likely be a large advantage or disadvantage.
I personally prefer a mouse and keyboard for everything I play, and I would certainly perform my personal best using it in all genre's. However if I were to compete against a console gamer who's personal preference is a controller, I believe in most multiplatform genre's our input methods would be mostly moot.
If you honestly want to keep your panties in a bunch over such an impersonal point, or simply get pissed off at what you think he implied by reading between the lines, feel free to continue.