It's the case that Colbert's ratings have gone downhill and the show isn't very good or even all that funny. But it's also the case that the show has a very loyal Liberal fanbase (not the young people that Colbert thinks they appeal to but rather old people who still watch TV).
I think it's very, very suspect that Colbert just happens to get the boot RIGHT AFTER the merger and Trump settlement, I mean come the fuck on. Even a child could tell something's wrong here. The fact that Trump praised his cancellation and said other hosts were next almost implies he was directly involved in the decision. But it could go either way. Maybe it really was a financial decision and it just came at a very, very tone deaf time.
Now, if Jon Stewart gets canceled, you'll know for a fact it's to silence him, because Daily Show ratings are at an all-time high. And unlike Colbert, Stewart actually gives a shit and isn't just a corporate shill.