Why does everyone hate upvoting posts?

I've made a few posts in the recent days and all of them received significantly more comments than upvotes. Most comments are positive ones but for some reason those people are not upvoting the post. And it's not only my posts, most of other posts have similar low upvotes/comments ratio.

https://preview.redd.it/l9izd4bgl7f71.png?1049&format=png&auto=webp&s=16d94f0882060e0e7955d80bec36657bb40f747b

I understand that you get moons for comment karma so it makes sense to comment more. But if you like the post and agree with it, why don't you upvote it? Those few upvotes are not really going to affect the overall moons/karma ratio but it will discourage people from making posts.

Update: Reddit and I are on the same page about this :D

https://preview.redd.it/g9vcv69tn7f71.png?692&format=png&auto=webp&s=b0bbec165e3d9e02e6d5d31fbe10748a2f9853b3

Update 2:
During the last distribution the total karma was 5,768,798 and 1,753,899 moons were distributed to users. If you downvoted/didn't upvote 1000 posts that would increase moons/karma ratio only by 0.017%. So instead of 100 moons you would get 100.017. Is it worth it?