I think you are disregarding the fact that libido is not a strictly biological function. You claimed that your libido had decreased with each new drug. Sometimes it's necessary to look at the simple fact that libido will naturally decrease in women over time.
Also, I don't know when this 15 year span was. There have been many advancements in oral contraceptives since they were introduced. Some of the brands that were causing problems for you aren't necessarily the only options left for women today.
Excuse me if I'm misdating you because you didn't provide that information.
Also, because not every women experiences decreased libido, and not every woman stops having sex while on oral contraceptives, I don't think that the efficacy of Oral Contraceptives is based on women being forced by the evil pharmaceutical companies into unwanted abstinence.