There are a lot of moving parts and nuances to this. Relationships can be very complex and there is no one-size-fits-all.
IMHO romance/sexuality is what makes our special someone special and what separates that relationship from all the rest. If the sexuality is gone, then that person becomes just another friend, just another roommate, just another person at the dinner table over at family get togethers and sometimes just another person on the street.
I think where some of hostility and animosity you refer comes from was stated by
@Jamieboy in post #9.
The bad vibes come from when one party declares the sexual component of the relationship over, but then expects the other to completely accept that and continue with all the other aspects of the relationship as if everything was just hunky dory.
I'm sorry, if you expect me to rub your feet and back at the end of a hard day, change your flat tires alongside the road in the rain, go out into the night to get you diarrhea medicine, cuddle you and tell you how much I love and care for you, unclog your toilet and kill spiders for you, you're going to need to be addressing my needs as well.
If you expect me to be sexually exclusive to you and expect me to love and cherish only you, then you need to be meeting those needs in me as well.
I don't have contempt or resentment for people who are not sexually attracted to me. 99.9999% of the Earth's population are not attracted to me. No hard feelings.
But if you expect me to provide you with all the trimmings and all the benefits of a full-service relationship but you wouldn't touch me with a 10 foot pole - yeah, sorry, that ain't gonna work.
And unlike many here, I do not believe that age, health or medical condition is an excuse or exemption for denying your partner physical intimacy. Yes, those things may prevent actual PIV intercourse, but PIV is just one facet of a huge spectrum of physical intimacy. There are countless other things that can be done to show physical affection and intimacy. Many times it is the thought and effort that count.
Personally, I would much rather get a HJ from someone who was sincerely desirous of me and wanted to touch me and be with me than someone who says, "OK fine, make it quick, my show is coming on in ten minutes" and then spread their legs for me to climb on and use their body to masturbate with.
So the animosity and resentment you are picking up is not from not having sex per se. One can have a loss of emotional connection and loss of warm and close and intimate feelings from lack of sex, but that is not often the root of the hostility. The hostility and resentment is from the rejection and not trying to meet the other's needs while still expecting the other to continue providing all the other benefits and expecting the other to continue joyfully providing them.