Whatever these women say is about THEM, not about you, even if they say it's about you
I would definitely recommend doing some research, because then you can say that you really do have an informed opinion (deciding on intervention without looking into the alternatives is not informed, it's biased) about your decision, and you can then just respond with "I've done my research, I'm informed of the risks and I will answer to my children only".
No one individual woman is responsible for her birth outcome. Whether its natural or medical, even if you have a freebirth, the birth experience is a product of a society, of a culture and the structures within it. Small 'p' politics is very much part of every birth in this country, whether you know it or not. If you can distance yourself from the blame, shame or regret then you are actually in a much better place than a lot of other women who have been damaged by the same experience, and I am genuinely very happy that you are in this space about your previous birth
You really don't have to answer to these women.