I would like to inquire and suggest the following:
1- Inquiry: Yes, it is weird! There is only an upvote button on the comments! Why downvotes on the comments were not considered?
2- Suggest: including a downvote button on the comments is vital! I read many inappropriate comments here and there. Some People just have big ego, others are disrespectful, some users are not cooperative enough with other users (especially the newbies). Including a down voting button on the commanets and link it probably to the total number of reputations (for example every two down votes on a comment would elemnitae 5 reputations from the total score) would improve, significantly, the quality of the comments –scientifically and ethically.
I know that somebody will say that you can flag a comment. This is correct, but this is not enough to improve the quality of the comments.