Tether is as legitimate as any non-US, non-regulated, company unable to do business with reputable banks or auditors could be. The NY AG case went a good way to legitimize them.
> “Bitfinex and Tether recklessly and unlawfully covered-up massive financial losses to keep their scheme going and protect their bottom lines,” said Attorney General James. “Tether’s claims that its virtual currency was fully backed by U.S. dollars at all times was a lie. These companies obscured the true risk investors faced and were operated by unlicensed and unregulated individuals and entities dealing in the darkest corners of the financial system.