That's actually because this "like" model is designed based on a martingale, a hazard game with a betting system. Just instead of you getting returns on your betting, you're getting (virtual social) returns on other people's bets.

We're literally wired to seek social approval, a strategy that has made civilizations work as well as they have.

Finding meaning in other people liking things you've done/said/found seems extremely human to me.