Because the problem wasn’t that the government spuriously massacred a bunch of people arguing for democracy. It was the insinuation that people died where Mao founded the Republic of China, obviously.

I think it’s important to be accurate when recounting history, and I think that saying that most people were murdered by the chinese government as they moved towards Tiananmen Square is better than to say that they were murdered at Tienanmen Square. Same as specifying that Auschwitz was located in occupied poland, not Germany.