While I think this touches on a big part of it, I think the bigger thing is the need for identifying stations for accountability. If there was a protocol that emitted an encrypted blob followed by cleartext/phone callsign, it would probably be more acceptable.
No. It's obscuring the content or meaning and it's not controlling a space station:
§97.113 Prohibited transmissions.
(a) no amateur shall transmit
(4) Music using a phone emission except as specifically provided elsewhere in this section; communications intended to facilitate a criminal act; messages encoded for the purpose of obscuring their meaning, except as otherwise provided herein; obscene or indecent words or language; or false or deceptive messages, signals or identification.