Re: Thoughts on this
In many ways my wife is similar. The big difference is that she does greatly enjoy non-sexual intimacy during the week. Fairly frequently she even suggests that it would be nice to get to bed early for sex - but very rarely does she actually go through with it.
I think she never accepts my offers for sex, because if she wanted sex she would ask.
She clearly thinks that the purpose of sex is for both parties to get off, and that doing this once a week is reasonable. Sunday afternoons work well. Its after doing the grocery shopping and lunch, but before we get diner and watch a movie in the evening. A good efficient time for sex.
Since the function of sex is getting off, and she has found techniques for us to both do this with a minimum of effort, she sees no reason to change. She seems a combination of confused and hurt if I indicate that I don't really enjoy HJs - after all I get off so what could the problem possibly be? Often when I am doing things for her, she wants me to go to using the vibrator that gets her off quickly.
When I've turned her down for sex she seemed honestly confused. I think sex is so different for her that she can't imagine that what we are doing isn't a great sex life. Can't imagine why we would have sex at anything other than the most practical time in the week.