To a goldfish in an aquarium, it is also very natural that food appears from above, as per magic.
My intention was to indicate at least a fraction:
There must be /some/ western culture that has been successful because it [that portion] is what humans naturally gravitate towards.
My accident was to imply that western culture has been wholly successful:
There must be some-western-culture that has been successful because it [all of it] is what humans naturally gravitate towards.
Sorry to any readers in the future, I deserve the replies I got today in this context.