It deserves mockery! Why in the world would people get so exercised about the characters in a TV show?
Looking back, it seems pretty silly, now. The only way to explain those times is to note that MST3K fans were (and in some cases, still are) remarkably passionate about the series. Plus, it seems to be human nature, when confronted with a dichotomy, to take sides (tastes great! less filling!) or to at least compare and contrast. In a situation like that, somebody, almost unavoidably, will say “host A vs. host B: discuss.” Those elements were all that was needed, at the time, to spark a very ugly situation. But that was a long time ago.