Welcome, good-faith commenters. You've taught me much.
Comments aren't just correspondence, but co-publishing. Therefore I reserve the right to decline to host a comment if doing so would make me feel bad. This is completely at my whim. A creative needs to feel good about his work in order to continue it.
This has nothing to do with fairness or freedom of speech. I must avoid the depression and obsession that ensues if I feel my work disrespects truth. I'm already overcritical of my work; graffiti makes me want to torch it.
I might decline a comment but respond to it with a post. I might be unwilling to host a comment that would be fine on my forum. I feel less responsibility for what's written by others on my forum than for what's approved as a comment under one of my posts.
I may decline to publish a long dissenting comment if I feel the position is unreasonable. In that case, I suggest making a short comment summarizing your position and then linking to your own platform. I feel less responsible for endorsing your position if fewer screen lines are devoted to it. Readers can judge for themselves quickly and move on.
If I do publish your comment, I may rebut it with a strong opinion, loosely held. Don't assume the certainty I assign to a statement. I am a probabilistic thinker who finds adding qualifications to a low-certainty position to be like adding bling to a low-value car. Antagonistically mistaking direct language for certainty is a quick way to earn my contempt. Direct language and clear thought are identical.
Many incorrect positions have worthwhile truthful aspects. Just because I can't endorse your position doesn't mean I think it's worthless.
As for extended discussion, forums are better suited for that. Link to a change of venue before a thread becomes unwieldy.