Okay so statistically speaking, in agrarian/preindustrial societies more than 9/10 of them would be farmers, which means they would (hopefully) have pitchforks. And if you don't have a pitchfork, then you shouldn't be at the front because then you'll be blocking someone with a pitchfork. You can carry a torch or something maybe.

Also, some farmers might have multiple pitchforks (so the wife/kids can pitch in, I'm pretty sure that's the literal meaning so not a pun BTW), and would know you probably don't have a pitchfork so would kindly bring along a spare to the angry mobbing.

Point is, the stereotype is at most off by 10%.