"where exactly are these hordes of people telling women to shun personal ambition etc? They have been singularly absent for me."
Unless you have been living on a desert island or perhaps reared in a tribe of Amazon warriors, I will have to presume that you have been socialised just like the rest of us and are just playing dumb here.
"I loathe sports. Always have. Not because "girls are told don't do sports" but because I find sport pointless and boring."
Let me guess - You are rubbish at math, don't like sciences, and read chick-lit? I am
that you are so perfectly conditioned in your gender role and still think that it is all a biological part of you, nothing to do with how you are raised. How fascinating.
Equally surprising that anyone can claim in this day and age that sports are "pointless". Have you never heard of the benefits of exercise - for your heart, muscles, posture, strength, flexibility? Seriously? 
As for "boring", well, I can only assume that you haven't tried many (any?) sports. I have done a lot of windsurfing, sailing, & skiing, scaled down mountains, competed in several disciplines like swimming, tennis, and basketball. None of it has been boring.
If all sports in the world are boring, what is fun in the world of ALass? I would be interested to know.