and that’s because (1) the purpose of this website is to share things that bring us joy and (2) likes don’t share things or ensure something is seen by more people, not like they do on other sites. so, when so many people decide to only like a post and not share it (i.e. not reblog it), that tells the creator that those people didn’t think their hard work was worth sharing with others. that’s discouraging. 

and the creator isn’t the only one that gets something out of that. you get something, too. you get the joy of sharing something you like; that’s a meaningful experience for both you and for the creator. and that experience—that interaction—encourages the creator to create more, and so there’s more joy to be had for both you and the creator.