I think with Dr McKinnon its 2 things:
1. The first is that there remains much debate as what ought to be the requirements for a transwomen to compete in female sports. The fact that the UCI / IAAF / IOC etc have various guidelines does not mean that people have to agree with them. They are very controversial and I know a great number of cis-people who are not transphobic (and indeed transwomen) who consider that the present regulations are too lenient (or indeed too strict).
I don't see the article as transphobic at all. In fact its interesting that they even pointed out "After concerns about transgender athletes having an advantage in the Rio 2016 Olympics, Loughborough University in England conducted a study by reviewing 31 national and international sporting policies, including those of the International Olympic Committee, the Football Association and the Lawn Tennis Association. The study concluded that a majority of policies unfairly discriminated against transgender people, especially trans women". For foxnews it actually appears to be surprisingly neutral.
2. I'm afraid she doesn't do herself any favours on twitter. Last week she suggested that the only morally acceptable sexuality was being pansexual. Now whilst I can kind of see what she is on about (ie. that you should fall in love with a person, not their gender or their genitals) funnily enough heterosexual / gay / lesbian people don't like it being suggested that they are immoral merely because they are attracted to a certain gender.
