Why that "natural birth" fever??

I've read so many post of women beating themselves for ending having an epidural or a section and some other thinking they are better mums or stronger than the rest for going full pain. I respect all the choices, but why that enthusiasm for going "natural"? I mean, if you go to the dentist to get a tooth removed you don't even think of doing it without anaesthesia, right? I just want to understand, no offence, please.