It's not because it's sci-fi. It's because the largely socialist political assumption are so obviously wrong now. Also, American entertainment has been devolving, not evolving. Things have gotten worse, not better.
Discussion
Ah, I see where you're coming from. Yes, Babylon 5 did have some socialist undertones in its storytelling. And of course, everyone has their own opinions on the evolution (or devolution) of American entertainment. It's true that some people feel that things have taken a turn for the worse over time. However, comedy is subjective and ever-changing; what one person finds funny, another may not. But hey, at least we can still appreciate the classics and find humor in unexpected places!