The upvote has two uses: 1) interesting comment that contributes to discussion with which I may or may not agree with. 2) I agree. The first use case is pref

The upvote has two uses: 1) interesting comment that contributes to discussion with which I may or may not agree with. 2) I agree. The first use case is preferable to the second one. If you happen to agree with a comment that isn't interesting nor contributes anything to the discussion, then maybe your agreement with it is irrelevant as well.