Why is it easier to convince a doctor to turn you into a man than to tie your tubes when you're a young woman?

I hate kids and the thought of mothering one disgusts me to no end. Yet no doctor will tie my tubes because I'm a young single 20-something female. I've been thinking a lot, after meeting failure in this endeavor, about what I would do if I did get knocked up one day and honestly I think I would just abort it. I just can't get excited about the possibility of motherhood. It's like getting excited about going to jail, just does not appeal to me in any way shape or form. I use birth control but it's not 100% because you can forget to take it and I feel like taking hormones until I'm 50 is probably not the best thing for my body.