Just saying, 'I'm offended' and leaving is no help to anyone.
Not true. It's often of help to the person who said it. If someone stands on your foot, saying "ow, dammit, you stood on my foot" is a pretty natural response, it's more cathartic and comfortable than standing there and being injured in silence, and it gets the message across - "you hurt me, watch your feet more carefully" and can prompt an apology, which can further alleviate the annoyance of a bruised toe. None of that requires a detailed explanation of why someone in steel-toed boots has an edge on someone in sandals.
To expand the metaphor further, imagine that someone stands on your foot while dancing. You can stay there, patiently teach them the dance steps, and put up with being stepped on more, and getting more bruised, and devoting a night that you intended to enjoy to someone else's education instead, or you can say "ow" and step back and find a new partner. If you're up for the teaching, more power to you, but no one has the right to demand it of you.