It's a little bit China's fault. Because of competition between the Chinese manufacturers, it's not uncommon for a particular factory to underbid the price, produce exactly the requested good for a while, and then start quietly cheapening the design so that they can finally start making a little money.

It's why, if you're going to manufacture your goods in China, you need to regularly inspect the factories.

But, yes: the other problem is that China makes some cheap things cheaply because that's exactly what they were asked to do.