Let me rephrase it a little: "Everything is great BETWEEN US except the sex." Can THAT be true?
I think your no-sex partner can be a great parent, a great companion, help with the housework, carry on a great conversation, great at his/her job, be a great son/daughter to his/her parent, be deeply religious, tidy, thrifty, clean, brave, and reverent.
But can things really be all that great between you two if you're not having sex... or having it only a couple of times a year, or having it only after begging, pleading, and other humiliation?
I look back at me and my bf. I would have said everything was there, in place, and good except that we weren't having sex. But in spite of the fact that we had/have many shared interests, there was always something missing at the heart of things. I know he loved me and in fact still loves me. But say we sang in a concert together-- it's so much fun, getting all dressed up, performing, going out with the choir afterwards, congratulating each other, enjoying the adrenline buzz... but you get home and no sex. No culmination of a great evening. No sharing the ultimate closeness.
Or another thing we both like to do is grocery shopping. Going to a gourmet market and buying an assortment of goodies, coming home and cooking them, having a great meal, maybe watch a fabulous movie later... then I go to bed and he follows three or four HOURS later. That kind of evening just left me sad, not fulfilled.
So if your partner is a great parent (which my bf is), a great child to his/her parent (which my bf is), shares your interests, likes the same kind of lifestyle you do, shares or at least is interested in your religion... but doesn't reach for you sexually in the most intimate kind of sharing... how great can it REALLY be?