Well because the media overall are liberal, and liberals run Saturday Night Live, and liberals run NBC, they think their crap is funny.
I don’t know about the ratings for this show. I have a feeling that the people who run NBC would actually be okay with subsidizing the show, because of the alleged biting political commentary.
I recall reports have Colbert, Jimmy Kimmel kimmel.Et cetera actually are losing money for their networks. But the thinking is they stay on the air,because they can make their political jokes and pretend that they represent the mainstream. Although I know Colbert’s gone soon.
Off topic, but it’s stunned me that the liberal view of Colbert’s being cancelled is that that was a type of censorship. And of course that alleged censorship was blamed on Trump.
They think it's helping them but it's actually hurting them because they are seen as elitist.