If you want to have a discussion about something, it belongs in chat, not in the comments section of a post. Comments are designed to be temporary and need to be reserved for very specific reasons including requesting clarification of the post or asking for greater detail.
From the comment privilege page:
When should I comment?
You should submit a comment if you want to:
- Request clarification from the author;
- Leave constructive criticism that guides the author in improving the post;
- Add relevant but minor or transient information to a post (e.g. a link to a related question, or an alert to the author that the question has been updated).
When shouldn't I comment?
- Secondary discussion or debating a controversial point; please use chat instead;
Starting a discussion of how you feel about the subject is inappropriate and a moderator is in their right to remove such content as it is noise. On top of this, these comments are often very distracting and potentially annoying to the OP of the post.
If you'd like the content of the comments, it's possible to get that for you as they're still accessible to moderators but I've seen the discussion you're talking about and agree with the comments' removal. Once this discussion is over, as far as I'm concerned, the entire chain can be removed... which they now are.
As I said at the start, save these sorts of conversations for chat and please don't use comments to discuss this.