I use it because my stupid lock button is busted on my iPhone 4. It works nicely, except there's no way to turn the iPhone back on except plugging into power.
Apparently, It's not just the Chinese. I'm from Malaysia and a lot of folks here, especially young adults and teenagers use it this way.
Like the quote from article said, they fear that the home button may break when it's used.
I'm sure they use it to bypass the fingerprint scanner.<p>Oh sure, the scanner may be turned off but that doesn't necessarily mean it's not collecting fingerprints anyway. Perhaps the Chinese are more realistic about pervasive surveillance than we are.