I've seen many SE users (even high-reputation and experienced users) upvoting to counter a previous downvote. This mean many up-votes are being cast based on the fact that someone else dislikes the question.
This leads to a biased voting system. I understand this encourages new users to continue using SE. But votes based on another's vote is not constructive at all.
Analogy (TL;DR): You work for the local jury. A defendant is brought into court for some legitimate crime they committed. But you dislike the prosecutor, so you vote to release the defendant.
Is this proper use of upvoting?