Comments are different from posts. The comment needs to have content to be valuable. With a post, you don't need to add any editorial; it's the thing being post

Comments are different from posts. The comment needs to have content to be valuable. With a post, you don't need to add any editorial; it's the thing being posted itself that needs to be interesting - but not to everyone. If no one finds it interesting, people won't vote for it, and it'll never reach the homepage. But given that people did vote for it, obviously a number did find it interesting.