I wonder how accurate that survey is, I wouldn't expect to see such a big difference between Mormans and Jehovah's who have basically the same kind of methods of indoctrination and ostracization.
I suspect that those without experience with religion just have little inoculation against its manipulations and scammy behaviour
I'd say my first real encounter with religion was in the exact sort of situation we are talking about now, an evangelistic religious instructor in my primary school. Up until that point I was told that god existed and was a thing but religion itself was pretty murky as my Dad was a closet atheist and my Mum a social or default Christian (non-practicing).
Funnily enough though that encounter set me on my path to Atheism, I had up until then taken the existence of god as a given but the evangelist wanted to sell the whole fear of hell bulls*** and the concept of sin which was completely at odds with my own moral understandings at that age. I was taught right and wrong based on empathy, the whole "How would you feel if someone did that to you" sort of thing. So the whole right and wrong based on a reward/punishment system felt wrong to me and then when you find out it's rigged from the start and you are born with sin I started thinking that this whole religion thing was a bunch of crap. Also the whole infallibility of god followed by a big list of examples of where he failed kind of stood out as peculiar.
I was about 7 at the time and it took me until probably 13/14 that I decided if I didn't believe in the religion then there wasn't any point in believing in the existence of god