Kip is right. Not only the tunnel coverage, but many other topics here on SLOG show that Cap Hill people can't be bothered with anyplace in Seattle that's not up there or isn't adjacent to it (Downtown, U District). It could be that getting around town from up there is a drag, what with all the bad traffic and buses that only go to Downtown and U District, but I think a lot of Cap Hill residents are also insular and a bit stuck up. Fremont might claim to be the center of the universe, but that attitude is more clearly expressed in Cap Hill.
That said, I think a lot of people exaggerate the distance/trip to Bainbridge. I had friends in Bremerton (the ferry trip takes twice as long) and my wife and I were the only ones who would visit. If you do it occasionally it's not inconvenient, but a lot of people just don't want to set aside half a day to do it. They just want to be able to drop in or call and arrange to meet up someplace. Hard to do with folks who don't live in town.
My friends (who commuted to Seattle every day) bummed out on this enough that they eventually sold their house and moved back to Seattle. The commute probably drove them to it, but they also just wanted to see their friends more often.