It's pretty simple to tell if someone is legitimately transgender which is why I don't see it being such a big deal. Those people already have it difficult enough, I can imagine athletics or any hobby is a nice escape from the crap they have to constantly deal with. It's a shame they are getting hassled there as well.
Olympic athletes of all types are already so far removed from what a normal human is (edit: capable of ), I don't really care about their precise gender.