I would definitely say it is not. Upvoting and downvoting are not similar to liking and disliking. Those are subjective, while upvoting and downvoting is / should be objective. The goal of AU is not socially, but informational. Of course you communicate, and probably you will like the behaviour of some users more than others, but that is secundary and we do not have "friends" here in the sense of social networks.
(Too much) personal information is rather distracting than useful in the goals of this site, and decisions and actions should not be based on- or influenced by that.