Yeah, "natural" is waaaaay too ambiguous a term to be defined strictly. What "NCB" advocates are for is really what might be called "normal birth," but then that would get folks up in arms about being called "abnormal," and it's a whole big (and pretty much the same) mess. Someone arguing that Tylenol makes a labor "unnatural" or "not natural" sounds like she is caught in the barrel mentality with the rest of the crabs. Either she is some kind of extreme purist or she is trying to justify all the more injurious interventions by equating Tylenol with them. It's not supposed to be a game show with winners and losers, either way.
The bottom line (IMNSHO) is that we should all be "for" drastically decreasing the use of unnecessary interventions and promoting labor coping and birthing techniques that lead to the best outcomes for baby and mother.
Even in my "perfect world," there would be C/S, the use of some drugs, etc.-- even in the case of "maternal choice" or exhaustion when they're not strictly "necessary." However, they would be relatively rare and/or last resorts-- at least performed at a frequency commensurate with their risks.
At some point this gets to be like 9th level veganism-- not eating anything that casts a shadow. The bottom line is not fanaticism, it's improving the health and well-being of women and babies.
Really, this whole focus on pain and who is a "real woman" and who is somehow not... No. That's a smokescreen designed to divide and conquer.
Okay, off my