Completely agree. Creating a user base is something else and compelling/bugging someone to upvote is a shixxy idea. Definitely there should be some ethics or mannerism. Good content needs to be noticed but begging for upvotes is just unethical. If I like some content then only I would upvote it based on its merits, whats the point playing an Upvote n upvote game.
Also I hate people who comment "Nice post" or "Thanks" and then upvote their own comment which consist of 1 or 2 words at the most. Though keep hoping for the best.