I can't answer for everyone, but for me, it was not a case of 'bait and switch'! In the early days I did have desire, and I did want sex more. I just don't know what happened to it.
In the early days I to had desire and wanted sex more. It was all much easier then. It was carefree in aspects. Then life and all its ups and downs twist and turns Sucesses and failures and responsiblity came along and stomped out the fire of desire. And want of sex dwindled as my thoughts of it did Why? Having sex was put on the chore list right below vacuming and above sorting the socks out. Sex became a responsibility of being the wife. The same as changing a dirty diaper was of being a mother. Sex did not seem as important as getting up with the baby in the middle of the night. Sex did not seem as important as sitting up and watching a disney movie for the 80th time with your child. Sex did not seem as important as the housework that needed to be done after the kids went to bed. Sex did not seem as important as sleep after two days staight of vomitting,feverish,wailing kids. Sex did not seem as important as getting the kids school cloths washed and H uniforms cleaned for the next day after working 10 hours. Sex did not seem as important as sitting up worrying about your 16 year who is not home yet. Sex did not seem as important as a late night phone call from your child away on vacation wanting to tell you what they did that day. Sex did not seem as important as sitting down and writting that letter to your grandmother while all was quite to thank her for the $20.00 she sent you and tell her how much you missed her. Sex did not seem as important as taking that long bubble bath to relax and gather your thoughts after a long day of yard work followed by making dinner. Bathing the kids and doing laundry and finishing the project that you did not get done at work. This list could go on forever. So that is why I no longer have much desire.