Cyberpunk 2077 has tons of absurd and outrageous content and ideas that are not humorous, it is like that because to us these fictional, normal concepts to the people in the Night City, are outrageous. The vibe is same in the MGS4 TV. They seem to be presented as normal TV for the state of the world/America MGS4 is in. The humor, itself, is layered to the sad state the semi-futuristic world has gone to. Just because something is absurd, does not mean motivation for that is to be analyzed as simply. Many in-universe earnest things are absurd, if not slightly funny, because the reality the people have "progressed" to in many futuristic tales.