They're making the (possibly false) assumption that density will stay the same, so size must grow with weight.
Of course, it's equally likely that size will remain constant. It changes or it doesn't -> 50/50 odds. Until the point it all collapses into a black hole.
You should never give up your right of way under the guise of being courteous. It's unsafe for everyone, and even in the best scenario it still causes frustration to all drivers involved.
Dont be polite, be predictable. And that means taking the right of way when it's your turn!
6 deserves what they got.