For others like me interested in the exact example; it's about the difficulty of designing a trash can that smart bears cannot open and dumb tourists still can. You cannot create something too secure if you still want dumb people to use it as well, due to the overlap.
The quote is not really saying dumb people will break / nullify security, like I read in the above comment, but more that they just will not be able to operate it.
Do you have a source for that? I cannot find anything about it online in Google, Wiki or even in ChatGPT delusions.