Originally Posted by
Zfz
Hardware bans require hardware IDing, which means the client side software needs to access the hardware information unrelated to the game. The simple act of collecting information like that could be argued to constitute a violation of personal privacy. Japanese companies and its government is especially sensitive to that, so much so that the Japanese even question whether their ID number, called "My Number", is potentially a violation of privacy.
The only way to really get rid of bots is to have a constantly updating encryption protocol protecting your in-game communication. But at least at the moment, it poses a heavy burden to both the data center (which has to decrypt connection packets from potentially millions of players at a time) and the client software, plus add delay into an already extremely time-sensitive application, that online games generally don't use them.
I'm sure the technology is available, from a big data perspective, to retrospectively inspect the server log data and find groups of player characters that all perform very highly consistently, and thus ban them as bots. The question is whether Square Enix even thinks it is a problem (they're getting the subscription anyways) and whether they have the expertise in-house (otherwise it will be very costly and risky to source something like that externally).