I believe it has a lot to do with the individuals involved in the relationship. Some people are just not able to handle distance. Either they will give up thier pursuit, or they will give up thier partner. I do not have any doubts that my husband and I can handle distance.
Early in our relationship, I went to sea for 3-6 weeks at a time to work. No phones or emails. I came home from work and slept for 2-4 days solid (after showering for an hour!) Then we had about a week together (around his work schedule) before I left for the North Atlantic again. I loved my work, and both of us were busy enough that it worked well for each of us. When I was laid off from my job, my husband's job required travel. For the next year, he was home for less than 50 days over the entire year. By days, I mean he might fly in at 11pm, and leave again the next morning. It wasn't as easy for me, because I was jobless for part of that, and felt lonely, but as long as I stayed busy, everything was wonderful.
Then, we evicted tenants, who trashed the rental home to the point that it was nearly condemned. In the same week, we obtained a special puppy for SAR work (my 'hobby'), and my husband was offered a far better job 12 hours away. I went to the rental house (3.5 hours north) with 2 dogs and the puppy while hubby went to his new job (10 hours south) with our cat. I worked 16-18 hour days to repair and remodel the house and get it on the market. He was busy with his new job.
We were both happy with our lives when we were single. Joining our lives isn't about leaving our single lives behind; instead it is adding another layer to who we are. We find that distance and traveling keeps our love fresh and joyful, but also give each of us the space and time to pursue our passions and develop ourselves.
One caution; any weakness in a relationship is intensified by either living together or by loving over distance. The tendencies and habits that annoy you when seperate may drive you insane living together, while issues like jealousy, doubt, and insecurity rise to the surface in a distance relationship. Communication issues may arise as well, since both partners have to work more to stay involved.
It is possible, but only if it suits both partners.