I see the "rep" and the "greenies" and the "like" options as ways one person can agree with the comment of another, and/or show gratefulness for a certain comment/view even when that comment/view might end up being disputed by others. It's akin to a "giving a prayer blessing' in my opinion, and I don't want to take away some person's desire to say "bless you" to another.
I use the "like" button, but tend to forget about the "rep" option.......sigh.......even when I read a comment that I believe deserving of a "rep" comment........by the time it occurs to me........I've forgotten where the comment was posted........
(one of the parts of growing older that amuses me..........I'm laughing, but can't remember why........)