Because the site of Worldcon is selected by members (i.e, sci-fi fans) of which China has _many_.
In fact, this whole debacle has hurt them the most since it seems many/most Chinese authors were excluded by default since the amateur self-appointed censors couldn't actually be bothered to figure out what disqualification criteria would be, just that it could be "sensitive to China."
In fact, this whole debacle has hurt them the most since it seems many/most Chinese authors were excluded by default since the amateur self-appointed censors couldn't actually be bothered to figure out what disqualification criteria would be, just that it could be "sensitive to China."