Maybe I'm missing something here ... men are getting smaller?
Yup, and it's a damn shame. It's mainly because of all the estrogens (read that as soy products) that boys are eating (sometimes right out of the womb). It's not that they don't have enough testosterone, it's that their estrogen to testosterone ratio tips too far to the estrogen side. They are being demasculanized.
The length of an average erect penis has dropped in recent studies to anywhere from 5.1 inches to 5.72 inches depending on which study you believe. Contrast this to the 6.34 inches in the Kinsey study. If you've got young boys, get them off the soy products and feed them meat as raw as they can stand it and raw milk if you can get it.