It's 4.4% usage rate worldwide. China is 22%.

Acording to Wikipedia: As of 2012, China had 568,192,066 internet users. 4.4% of that would be 25,000,450 users. Depending on what you're doing, leaving out 25M potential users might not be a good idea (again, depends on what you're doing).

Well, it's not like a double margin would prevent them from seeing your text at all. They only lose out on pixel perfection.

Leaving a few million users out of pixel perfection doesn't sound so bad. (And out of those millions, how many will actually stumble upon your web site anyway?)

I keep hearing this argument, and in most cases, it's invalid. For the average page, it's not 25M users but 4.4% of whatever the user base is.

These 4.4% more might still matter, but the cost-benefit tradeoff looks much different now.