When we were younger I think it was the emotional attachment that was missing that messed me up sexually. I felt physically attracted to my H and at that time I wasn't bored, but after so many years of marriage (42) I think a lot of what you say is true. At least that is what set me off into a MLC late in life. My H wasn't giving me any attention and I was certainly bored to death. The longer you are M the harder you have to work at not being bored. It gets to be kind of tiring trying to think of things to do to keep from being bored if the other spouse doesn't like to do anything but watch TV. It sure helps when both parties are working together to keep bordom out of the MR. And of course, no matter how long you are M, you still need that emotional connection along with the physical.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!