I don't know if 'great' dancers have more propensity to be single than the representative population group they belong to. Most 'great' dancers are probably congregated in age of group 30s - again a very favourable group to be single. I think may be the original question itself is wrong. Ask a wrong question and you will get wrong answers. Traveling is certainly a distinguishing characteristic but the rest of the reasons would apply to any randomly chosen group. I don't know enough to say that more 'great' dancers are single than not.
Also perhaps who is a 'great' dancer is skewed by the fact who people see and know. E.g. as I noted some where else, Manga was practically unknown here till couple of years back and I doubt if more than 10% of the dancers in the bay area have every heard of her. It is easier for those who are single to travel. Conversely the 'great' dancers who are in relationship are less likely to to travel, making them fall off the 'great' group