It's like Black Friday/Cyber Monday/any other "shopping holiday". There are discounts, so some people try to move costly one-time purchases and whatever else they happen to need at the time to that one date. Others buy more than they need because they fear missing out on the discounts (classic couponing addiction). Of course there's also a "buy nothing, save 100%" meme. It has nothing to do with being an obedient citizen. If you think Chinese people will do everything they're told to, you need to adjust your worldview a lot.

Amazon does compete in China https://www.amazon.cn/ but the ads I have seen put them in the "foreign luxury goods" niche, where the market is smaller and their competition are other sellers of foreign goods, like proxy buyers. Unsurprisingly, Amazon doesn't have a lot of experience sourcing the kinds of stuff most Chinese people can afford. What Amazon sells internationally is largely the same as in America; what Alibaba sells internationally is largely the same as in China. Neither is a great recipe for capturing a foreign market with different needs.