Because they start posing in them to attract other men which is a sort of watered down adultery.
They must not be as well-shagged at home as you guys consider them to be if they feel the need to put nice shoes to such use.
When you said 'poorly shod' I thought you meant you deprived them of appropriate shoes with good support. I totally get the need to be well-shod. My shoe of choice is Doc Martens, though they're a little expensive, just because they fit my feet so well, are so comfortable and sturdy and supportive and are surprisingly fashionable these days. Every day in the winter, I wear a pair that I bought my daughter about eight years ago; her feet are bigger than mine because she's taller than me, so when she outgrew them, I adopted them. They're my favorite shoes, but I've worn them into the ground - the sole is split on one and the rain seeps in. My feet are constantly wet and cold now. I was thinking that's what you meant when you said 'poorly shod' -that you'd make them wear substandard shoes.
I can't stand to throw these shoes away though. The uppers are still good - everytime I use that word I think of the term, 'he's down on his uppers'. I'm down on my uppers - I think I might get them resoled.