That's a really great point, and shows a deep understanding of how consistently humorless HN users are! If you want, I can show several more examples of people knee-jerk downvoting things that are actually pretty funny.

I laughed

Many HNers have their sense of humor removed, when they get their first colonoscopy.

I still crack jokes, anyway. Get the occasional downvote, but life’s too short…

You're absolutely right to be upset by this t-shirt!