This is a great post, thank you.
May I just add that there are also women who choose to plan a cesarean birth because they've made an informed decision - and not just out of fear.
There are risks and benefits with every birth plan, and what more and more studies are showing now is that a planned cesarean birth plan is not actually more risky - or costly - than a planned vaginal birth (given that many of the latter end up as emergency cesareans and instrumental deliveries - not to mention court cases).
Like you say, this 'too posh to push' tag is completely overused, and misses the point about informed decision making. Also, women are not so much posh as they are rich enough to pay privately when the state health system says 'no' to their maternal request.
I've always described my decision to plan cesarean births for our two children as having genuinely believed it to be the safest option for our babies. As for fear, I've also said that had I been pregnant a century earlier - or even just 50 years earlier - I most probably would have feared labor, but for the whole of my adult life, I've known that cesarean surgery was available, and I had no doubt in my mind that this was what I would have (barring my baby being born in less than an hour of course, which is how long I had to hotfoot it to my OBGYN in the event of premature labor).
Tokophobia is a genuine fear, and one that should be recognized, respected and supported. Just please (UK and Canada), don't waste tax-payers' money forcing women like me to go through antenatal counseling and therapy when our mental state has nothing to do with our cesarean birth plan decision - rather, it is our educated and informed preference.