People people? Us? Well, no, but thanks anyway.
T-shirts are great because they let the wearer say something to strangers before they get close enough to start a conversation. They act as personality filters. That can be real helpful if one lives around a lot of stupid people, which includes such places as everywhere. Small people will see the shirt, take it at face value, and either make every effort to ignore the wearer or say something like, "It really makes me sad that someone who appears so intelligent would wear a shirt that demonstrates such ignorance." That there is a motherfucker who deserves to suffer. Use your discretion to determine by which method they should do so.
Someone in the know, someone who GETS IT, will smile, make a snappy comment, or simply continue on his way showing no outward signs of recognition but knowing inside that maybe the entire world isn't filled with dupes, after all. And that might be the most valuable thing you could give to anyone.
So go buy some damn shirts already.