It’s true that both are security risks, and that Tiktok is even worse in general, however other proprietary social networks are also BAD and the proprietary algorithms behind them can all be used for massive user manipulation (control what they see, when they see it, and what they don’t see, combined with tons of personal and psychological data about each user). That said, another factor that might be overlooked is that it also depends on how easy a target something is. An app by a foreign government that could be used to manipulate citizens is a much easier target for “banning”. There’s probably much less legal obstacles in the way in this case, and less resistance against it.