NPR used to be publicly funded, much like the BBC in the UK. The idea was to offer objective journalism for the strength of democracy. It has helped a lot in the UK may have helped prevent the current disaster we now experience in the US. When that public funding started being removed, NPR had to start acting more like a private company, satisfying target demographics and seeking seeking donor support.

So, NPR pledge drives are in large part them trying to maintain an objective perspective. A feeble attempt, sure, but they are trying. Youtube is merely maximizing profit.