I think voting should be as what was originally set out by Reddit; I don’t know if it’s still in their guidelines. The voting system indicates the relevancy of the contribution and whether it adds to the discussion or not. Spam and off-topic contributions gets shoved to the bottom and everything else rises to the top.

Obviously most people on Reddit these days use it as a like/dislike, agree/disagree voting system as well.

Does Lemmy instance owners and community mods ban people for having a different opinion that’s so benign?

Some Reddit mods attempt to be authoritative and ban people who hold different opinions to themselves. I know I have and I stay out of subs that relate to politics, the news, and anything divisive really.