You're right, 6' tall is a bit taller than median, but well within the fat part of the bell curve. I am somewhat tall, but not particularly.
If you don't believe that your son has ever unintentionally seen down a woman's shirt, you are simply incorrect. Either that or he has never spoken to a woman shorter than about 5'6" wearing a low(ish) cut shirt. It just happens.
As to my being a pervert who can't get dates... I don't have that particular problem, and while many members of society dislike me for a variety of reasons, I have no evidence to suggest that undesired ogling is one of them.
Good luck with the bizarre moralism you've cultivated, I hope it serves you well.