I think shallow responses are kind of nice—sometimes you don’t have time to reply fully and it can be polite to just 👍. In fact, I sometimes go back to likes and flesh out the reply. So it acts like a bookmark, an ‘ack’ and a reminder to return. That’s not too shallow?
I have found my ‘likes’ since going all IndieWeb have become much more purposeful as I really make an effort to include a quote or something that highlights why it is interesting. This is a vast contrast to my Twitter/G+ experience.