I'm not saying you have to share every interest or even one single interest in order to have a good relationship. But that's mostly because people's interests aren't that big a part of their lives. I'm interested in computer games, for example, but I dont' dedicate my life to computer games to the extent that I became a world champion Starcraft 2 player. I'm certainly happy to date someone with no interest in computer games, because it's not important to me that they share that interest, as the interest isn't all-consuming. OTOH, if I dedicated my life to the pursuit of something, how the hell can I be with someone that not only doesn't have any interest whatsoever in that pursuit, but doesn't even respect the pursuit at all? Conversely, how can I be with someone who dedicates their life to something I have no interest in and explictly don't respect? If someone dedicated their life to building lifesize models of churches out of matchsticks, and spent the majority of their time, energies and thoughts on pursuing that hobby, I don't really see how I could be in a relationship with that person, being as I have no interest in lifesize models of churches made from matchsticks, and actually find the idea rather unpleasant. If I dedicated my life to the eradication of AIDS, it would be difficult to be with someone who thought that AIDS was God's way of punishing gays and found my pursuit of its eradication not only boring, but unpleasant, too.
It just doesn't make sense to date someone with such vastly different interests to you, let alone someone whose interests you explicitly don't respect.