I don't know, it could be due to men being portrayed as dirtier overall, or eating more overall.
I would guess it would have occurred from the same idea as women are female dogs, and cops as pigs.
Maybe since pigs are dirty animals and viewed as non-kosher (bad for you) by jews the term got picked up to make fun of those not good for you, in the same way kosher is used by non-jews.
That's my quick idea.
I would guess it would have occurred from the same idea as women are female dogs, and cops as pigs.
Maybe since pigs are dirty animals and viewed as non-kosher (bad for you) by jews the term got picked up to make fun of those not good for you, in the same way kosher is used by non-jews.
That's my quick idea.