There are other cases in which I just gave up on commenting because it was pointless.
The question itself is good, but the OP has already an opinion on the "correct" answer and basically has shot down or heavily commented any and all posts that don't agree with it.
I don't believe that this is an appropriate behaviour for the site. Comments are not the place for extended discussion or for mere opinion. The overall quality of the page is diminished by lengthy threads on the answers.
I flagged the post for moderator attention - at least to clean up the comment threads.
What else can be done to prevent or at least discourage this? Should be simply accept it as desired behaviour?
To be more specific:
If the above behaviour is accepted, then why should I spend 1h of my personal time to research an answer just to see it shot down by the OP because he doesn't agree? In my not-so-humble opinion this kind of behaviours tend to kill the community.