Fairly sure this would be rather difficult to implement from a technical stand point. I don't have the database in front of me, but likes aren't stored as individual pieces of information, such as posts or conversations.
So there is no way to associate a comment to a like, and since Likes != reputation; but are similar, such comments seem rather out of place. It also adds complexity to a system that works for its simplicity.
This sounds too much like vB5 to me...they allow commenting on a post and replying to a post within a thread, so at times you'll find conversations running off on all sorts of tangents.
Having said that, I would like a simple "Thank" system similar to "Like". Just a mention and a count, that's it. I still wish some of our members would even use the Like feature, but they are stubborn and hate change.