Heck and i always seen gpl extremists as crazy and release all my code under mit... And even so i refuse to use Ubuntu anymore.
You can never have everything; Ubuntu cares more about things that lead to adoption (i.e. usability), Debian cares more about purity.
The reason is that there is a proper organization that people trust and understand behind it (Canonical). People with incentives, money and ads.
Idealism has little to do with it. Granted, Ubuntu would be a bit less popular if they were as pure, but I don't think it makes much of a difference in the end.
Ubuntu wouldn't lose on mere "popularity" by being less pragmatic, they'd lose on hardware compatibility. It's pretty easy for a technical user who knows they want Linux to find hardware well-supported on Linux before they buy it, but the average user will come with a computer already purchased, and ask if Ubuntu works on their computer.
* excluding unity