Usually when I'm looking at a game page, in the top right there's an option to "rate this game".  However, I saw one that said "rate this bad game".  Why?

In the settings, for a project, it’s possible to change the word “game” for something else. For example someone might describe their project as an “experience”. In this case the text changes in a few instances.

I think that’s what happened here. OP changed their project from “game” to “bad game”, and that would be why this shows up that way.