Now before someone jumps down my throat for guessing people's motives on FB, I'm not knocking any particular motive. Whatever your motive for FB, if it serves you well that's great.
Having said that, this isn't entirely speculative. Factually some people feel disappointed when their postings aren't 'liked' by lots of people, or worse still when no one 'likes' them. Check your own reaction to no one acknowledging a posting of yours. Disappointed or indifferent?
The reaction to lots of likes is often to post more and more on FB, because all the 'likes' are quite seductive, and even addictive. The reaction to very few 'likes' is either to increase the volume of postings or else not post at all.
Anyway, the invitation is to check your own motive for posting on FB and see if it feeds your needs and wants. A clue to what that is might be in the way you react to the feedback you get.
P.S. Don't forget to 'like' this!