There is a tradition of keeping discussions on-topic or at least insightful. Off-the-cuff humourous comments are not really suited for a site like this. There are myraid places where that kind of expression is the norm already. This brings the benefit of increasing the quality of the discussion and results in there being less irrelevant text to sift through.
The comment was no more stupid then the parent comment. Now it is followed by your stupid comment. That the root of that tree has spawned so many stupid comments is a sign of its own stupidity.