I don't know but I've always thought this sort of place should have 4 buttons for a post. Relevant Irrelevant, I like, I do not like. This way people could disagree with something, but show that they think it is a good fit for the magazine.
I assume you mean, that you disagree with my idea. In this case I find it a somewhat valid use of a downvote within the system that I outlined. But if everyone downvotes what they disagree with, before actually engaging with the content, it turns Lemmy into just another echo chamber.
"Indicators of relevance" is fine in theory, but that's (allegedly) how it was supposed to work on Reddit too, and... it really didn't. It will turn into agree/disagree for a significant amount of people who either don't know or care how voting was intended to work.
You display the problem with that system in your own comment through your wording of "should be". Everyone knows what downvotes and upvotes should be, but due to their intent being unenforceable they just become "that person liked or didn't like this for reasons beyond my knowledge and understanding"