It's not the issue that's funny. Terri Schiavo and Elian Gonzales weren't funny either. All of these topics are very serious, and should be discussed. But not on every thread, especially when those threads have nothing to do with the topic at hand.
To quote you...
"Of course, it is entirely possible that the other person is ignorant (either by happenstance or willfully so), or is mentally deficient (incapable of understanding, or just flat-out nuts). But it is important to determine this by examination, and not to merely assume it because of their conclusions."