It could get annoying. Like replies that are just roller eyes, people who does posts like that would love it since it would simplify it even further and make it even more awkward to respond to it..
"Like" is good because it means you can give a simple response that you've read the post - or you just want to express agreement but you don't want to write "yes i agree" or "well said!" etc, which just clutters up a thread.
HiddenX is right.