I'm sure this is based off Majority rules where they look for a time when most of there player base is not playing. Which would make sence.
In fact, that's exactly what they say they're doing: Picking windows where the fewest players are impacted.
And they've even shifted the window in cases where they know special circumstances will cause different population patterns. I can't remember exactly which day it was, but they shifted a maintenance into the early morning in the US because some holiday was going to mean that a lot of European players would be playing during the mid-day.
Sure, it sucks for the people who play at the less popular times (beyond the normal lower population issues), but it does seem a bit selfish to say that its better to inconvenience 10 people than 5 people because one of those five people is you.