It could be users, contributors, time, money, or lines. Most or all of these apply to the difference between linux/git and average software. I don't accept it as an axiom that the biggest open source project in the world should be licensed the same as something in the first percentile of (pick one).
What I meant is that the software is used differently, and it is developed differently. It seems obvious to me that the ideal licensing for software that is vastly different from these examples of gargantuan/universal FOSS might not be GPL.
Three orders of magnitude of what? What is being measured? Do you mean that platforms are bigger than modules?