Not being an altruist, I've voted important for a very simple reason, aikido has been a very easy way to not be so isolated when in a new city for the first time. You can walk into most dojos and find yourself interacting with a new group of people who have at least something in common with you. As I'm effectively using them for my own ends, it seems only polite to at least try and get to know them and get on with them.
In addition, some of the more contentious threads have revolved around personal interaction, sensei's manners off the mat etc. If you're not willing to get to know them a little outside the dojo, how can you come to any real conclusions on whether they are the one to teach you best?