Earlier quoted context omitted.
It's not exactly purely an aspect of Western companies ignoring China or localizing property for China that is the culprit here. The Chinese government also makes it difficult, especially in the realm of internet services, for Western companies to play. I know plenty of American technologists who are well aware of Chinese internet properties, how could they not, when disproportionately many American technologists are…
Gmail technically isn't blocked in China, the GFW just messes with it sometime. Otherwise your comment is spot on: American companies don't compete in China not because they don't want to, but because they can't.
Check out other Asian markets (South Korea, Japan, Russia) and you may notice something interesting: many western companies failed to excel there too, even though there are no strict regulations.
eBay was not affected by GFW when they competed with Alibaba's Taobao marketplace a few years ago in China. eBay failed due to their own strategic mistakes.