Like buttons add another reply and take up space in the thread view with a message layer. Plus, IMHO they are for folks who are too lazy to write something cool. Just saying. This ain't Facebook
If you don't have something cool to say does not mean you can't like a post. Sometimes it is not necessary. You would would prefer the +1 post? In the music section the !ike button is good when you like someone's choice.
BTW, seems rather lazy just pasting videos from ones web site rather than writing something cool - just saying.