Instead of getting offended and thinking it's a binary thing and everyone is either asexual or not:
Remember that any time someone talks about hormones or neurotransmitters, there is no "right" just "average".
And the most unique human on the planet would be the hypothetical person who is dead smack on the "average" for the 100s of different ones.
Pointing out what causes differences isn't the same as saying we need to get everyone in the average.
Hell, the entire article is about asexual people wanting to know the "why"....
Did you even read it yet?