Board Thread:General Discussion/@comment-32094204-20171120170726/@comment-27958705-20171120180146

main reason it is "not added", i guess. u can use special:contact to request this feature.

there is already function to reply: reply button on every comment. sure, this feature can be added by easy way, but it seems to be pointless: whereever this button would be placed, it will be harder to press than regular reply button.