I understand why TGF would be a controversial choice, and I can see why it could be offensive to include as a world wonder, since it suggests the developers believe it "beneficial" to have. However, I can also see the reason it's included. It is a real thing a real civilization could, and did, build. Keep in mind that not all Civs symbolize Freedom and Liberty; there are Honor and Autocratic policies for a reason. Some civs can work fine (gameplay-wise) with their happiness bordering Very Unhappy. It is alleged that the Pyramids were built using slave labour. The Manhattan Project is a truly terrible thing. To the real life government of China, as well as players of Civs who would benefit (gameplay-wise) of such a thing, TGF would indeed be a world wonder.
TL;DR, it's evil, but so are some Civs.
(Addendum: I wrote this back on Page 2, but forgot to hit Post and went to a different tab for a while)