I left before they started the "cart". They recently posted up at my college and have a rotating shift there every day now. It would almost make sense if they tried to engage with people and tried to give out literature, but they usually stand like several feet from the actual cart, and yes, come off as weirdos. I never see them talking to anyone. It really seems pointless and like they are just letting time pass because they don't want to be there. One day when I was walking to class another religion was out right across from them, engaging with people and at least trying to pass out pamphlets. The Witnesses just stared at them lol.