Gringo, Personally I think this is a classic case of the difference between man and women expressing themselves.
While only speaking for me I cherish my OH, I am devoted to him. I have nursed him on and off for 6 years (he had some serious health issues some 6 years ago involving two major surgeries and I firmly believe that the general anesthetics and morphine triggered the dementia). Being a carer and dealing the more base issues of caring for someone means I cannot relate to him in that level of intimacy anymore. Intimacy is between two consenting adults. Rather than be hurtful - no I do want to have sex with you anymore - I chose to protect his feelings and avoid hurting him by making excuses and blaming it on myself. If the situation was reversed and it was me that was ill and he was caring for me (although he readily admits he could not do for me what I do for him) I know he would do the same.
This is not to say, as my original post that we do not still have that special closeness couples have after many years together, that deep understanding (on the good days) and the trust and bond.
Don't be misled, personally I miss that level of intimacy, I miss having him beside me as a decision maker, a leader, a listener, an advisor, a problem solver, telling me not to worry it will be alright in the morning. I miss him helping out, bringing me a cup of coffee in the morning, getting up before me and letting me have a lie in on my one day off from work a week.
I just miss him so much.