There are asexual partners who are still capable of having sex with sexual partners. That doesn't negate their orientation or the fact that they would be content with life if their partner decided sex wasn't important anymore. Fact is there are more sexual people then asexual and sex appears to be a really important in a relationship with a sexual person.

Asexual orientation can be complicated, too, because there are people who have experienced sexual-related trauma and feel that asexual is the appropriate word to describe feeling sex repulsed and not wanting to participate in sexual activities. I think sexual repression is on this line of thought. It all depends on who you talk to, though. Some people agree that PTSD/Trauma related sex repulsion/regression/whatever is inclusive and others do not.

I'm low libido/SO is too and I identify on the spectrum. I do not relate at all to a sexual persons interpretation of the importance of sex. I'm in a sexless relationship and have been for nearly a decade now and I'm happy. I have a partner that loves and respects me and I've actually grown more fond of him the longer we've been together. I feel really awkward when I'm with sexual friends and they are all talking about it because I don't relate to their experiences. I consider that as being "on the spectrum".