If the comments were not explaining/discussing the content of your post then I'm afraid those comments were just creating "noise" on the post.
The question and answer pairs are meant to assist someone facing the same problem. I doubt (under normal circumstances) that comments dealing with anything else other than the technical validity of the post would be helpful.
No one is required to explain a down or up vote - I'm not saying that it is a bad thing to explain your voting decisions but engaging in a comment debate about someone else's
decision is simply not needed :
...discussion regarding the validity of that persons reason for down voting.
I believe this is why someone removed your comment discussion.
Looking at your answer I believe one possible reason for a downvote is that there is no explanation of the code you posted.
As I'm sure you are aware - your answer is now at +8 - a couple votes short of a Nice Answer so a comment explaining a downvote IMO is already noise - it is considered a good answer - but there will always be someone who disagrees for some reason.
Comments should only exist to help understand the content of the post. If additional crucial information is discovered within a comment discussion then that info should be edited into the OP.
Comment threads containing
- "This worked!"
- "-1 for no free hand red circles"
- "Please work on your accept rate"
- "Why the downvotes?"
- "Check out my cool new site!
will not assist someone visiting that post 2 months down the line.