There's more than that. Here in my Brazil you have a lot of people who have not flown, are flying for the first time, only flew few times, etc... I would say 99% of people, regular flyers and all, have no or very basic idea of how a jet engine works, but there is a cultural thing at play here. Most Brazilians I have witnessed flying for the first time are so afraid, or stressed out about where to go, what to do, that none of them would ever even think about doing something like that.... because we don't do that period, and by that I mean throw coins on anything for good luck. As a mostly roman catholic country, what you will see if people doing the sign of the cross I don't know how many times, and praying the metal tube takes them safely where they are going. So it is not a negative thing about Chinese culture, but it is a cultural thing (and they must have addressed it for most part as now you hear about few cases only, as evidence, here we are, a world away, discussing it).

I am also concerned that just anybody has access to be able to throw objects into a jet engine.
This frightens me.
I have flown in places where anyone can walk out onto an airport runway....and they do!

technically correct--the best kind of correct

"the usual".. might of well get used to it...