Actually not always. I remember the good ol’ days of early Reddit where you could have astronomically negative votes on posts. Back in the simpler times when r/f7u12 and rAdviceAnimals ruled. It was only a feel years ago when they changed how upvotes and downvotes worked

Back in my day, they did have negative values. I want to say the EA Star Wars Battlefront fiasco was about the time they switched to hiding how very hated a post/comment is.

They used to not even be combined. You had separate up and down vote counters. The they combined them, and you could go negative and even get a cross it it was controversial.

I think you are right. Only comments could go below zero.