OF course you are definitionally correct about media being diverse and plural, but that's not really the point. 'The media' is used in the sense that Noam Chomsky wrote about it in Manufacturing Consent: corporate media, as profit-driven institutions, tend to serve and further the agendas of the interests of dominant, elite groups in the society. So the term 'the media' refers directly to those things you have mentioned: Fox/ABC/NBC/CBS/CNN.

Saying 'the media' is no more incorrect than blaming things on 'the man' or talking about 'the world' or wondering what the hell is happening with 'the economy' as 'the stock market' crashes and 'the government' fails to respond. Describing something that is plural and diverse as monolithic and homogeneous may be logically incorrect, but damn if it isn't useful when trying to have actual conversations.

I was just about to respond with something like that, but I see you've done it already, so... what he said.

Daily Kos, read the book by the founder.

The TV type media is the old guard.