>>96385957 (OP)
When done by genuinely clever or funny players, I love them. The street rat in our Conan game was Abu the monkey crossed with Daffy Duck, and was a joy to play with. The cowardly and conniving TIE fighter pilot named Wahlu Ghi led the team to victory when the chips were down.
But some players are just idiots or assholes, and if they make a joke character it is 100% because they aren't making a real effort, rather than being clever. Those players ruin it for everyone else. (Also, sometimes a good player will have a bad day, but usually a good player can course-correct later)