Most adults probably don't really know what a meme is yet either (they've probably seen a few, just don't really get it yet).
Sure, 9GAGgers are still at least capable of operating a computer or smartphone, but if you move even further down in tech-capabilities, it also becomes quite unlikely that those people will buy something from Microsoft to begin with.
http://9gag.com/gag/3325624/9gag-demographics
They aren't consumers. Beyond that, Microsoft isn't a company that targets individuals. They make their money from companies. They don't need to care about 22 year olds that have $100k of student debt and will pirate most software anyway.
It was originally coined by Richard Dawkins (way back, before he went senile); perhaps in _The selfish gene_. HTH!