Thanks for the suggestion. Its a really good idea! I upvoted your post.

There is some potential for "unintentional impact" as far as restricting user participation. A lot of new users start out by commenting on posts to gain recognition/followers/reputation. If they aren't able to comment on other people's posts, then it will be hard for them to work their way up.

I'll add a comment to your post tonight explaining my concern, then add it to the list. I think it should be considered.

[Edit] Your suggestion has been added :)