Im not sure what you'd call it when liberals listen to... Slightly biased news, and conservatives listen to people with clearly expressed political allegiances who refer to conservatives as "us", liberals as "them", and talk about how to politically defeat the other side.

Just because bias is hard to separate out, doesn't mean everyone's behavior and preferences are equivalent mirror images of each other.

You could find someone yelling about defeating conservatives on YouTube but that viewership is going to be lower than NPR... thus liberals prefer the less-biased sources...