Well, there are a lot of silly folks in the martial arts world. But by nature, the spirit of martial arts goes against poking fun at people.
Sensei is also not a universal term, although white people love to apply it to every martial art. Having practice martial arts but no Japanese martial arts, I have countless times have had to see white people be educated that no, we dont have senseis and dojos. When a white person walks into the Korean or Chinese martial arts school, calling the place a dojo, and asking for the sensei, it is a rather common scene, but still reflects their ignorance of that particular culture in question. Most get all huffy the first time you correct them also, lol.