there is a difference between sex and gender (sex referring to biological characteristics and gender referring to social constructs) and while i do agree with the point the article's making, the dismissive tone does bug me as well because there is that difference that most people don't really seem to acknowledge. biologically, this person is technically female but that doesn't mean the fact that he now identifies as male needs to be trivialized to the degree that this article did. regardless of his biological sex, the fact that he identifies as male and also had a child is frankly an absolutely remarkable societal achievement towards promoting acceptance of transgender individuals.
a friend of mine is also in the process of transitioning from female to male and initially he got heaps of comments from my friends along the lines of "well, you keep calling him a guy but he's not REALLY a guy, he's still got girl parts." in this case i ignored it and politely explained the situation cos i know most of them has never dealt with a transgendered person before. in terms of sex, he's female but in terms of gender he's male. since gender is the social construct, it's what everyone should be referring to him as. there are lots of other ways in which this gets all wishy washy and more black and white than it really should be, like how some states will not change your legal sex if you are transgender unless you get the genital surgery, even though there are quite a lot of trans individuals who really don't want genital surgery for their own reasons. i think it's neat to think about gender identity in terms of multiple dimensions instead of just the biological one.