The funny part is that this "conspiracy" was not even visible in any way in the original data the person found. It was just a strange spike in tips during rush hour. But then they started digging and this conspiracy-looking theory started popping up. I guess they could have stopped there :P Is that how some conspiracy theories start?
But in the end, it's a very reasonable explanation of different ways to calculate tip. I don't even think one way is "better" than the other. They are just different and there should only be one system in these kind of things, mainly because it's most unfair to the drivers.