No, you are. Be dismissive and glib, but don't be a passive-aggressive weasel about it.
You don't understand, clearly. I've never had a problem being an asshole to someone on this forum, to their face. The problem you might be having in understanding my sincerity is that I decide to respond to a longish post, and it takes time to respond to posts piece by piece, with my opinion of you point changing the deeper I delve into what you actually write.
So when I write in my opening bit that "I don't mean X" that literally means I don't want to come across that way, as it seems... when I'm writing that... that you are genuinely struggling with some issue, or engaging in my argument. Later in that same post I am no longer apologetic because I am increasingly convinced that you are arguing in bad faith, and entirely engaged in attention seeking behavior and making deeply insincere arguments, so my tone changes as I post.
Luckily for your narcissistic tendencies, I realize that arguing with people to change their minds is futile, and not even the point of a public disagreement, so you get your regular supply of attention, and I get to hash out my ideas of, in this case Shadowrun, for the benefit of myself and any curious readers of the thread.