You are not saying that there is a moral imperative for certain things to be fun, or to not be fun, as that doesn't really make sense (at least I can't make sense of it).

But that's exactly what I'm saying. When humanity becomes able to modify itself, what things should be fun, and will we ever run out of fun thus construed? This is the subject matter of Fun Theory, which ultimately determines the Fate of the Universe. For if all goes well, the question "What is fun?" shall determine the shape and pattern of a billion galaxies.