Embargoes against the Romulans by the UFP, due to their mutual hostility over several hundred years, and that it was also particularly strong. not only was it alcoholic, but it may have also had mild hallucinogenic effects on many humanoids.A trading embargo between the Federation and the Romulan Empire. watch inter arma einem silent lages it is stated explicitlyDue to the trade embargo between the UFP and the Romulan Star Empire; similar to the illegality of Cuban cigars in the US.I would imagine it would be similar to why you can't purchase Cuban cigars in the United States due to the trade embargo.Because Romulus is the Cuba of the Original Series era; there is no trade allowed with them because of the strained relations between the Federation and the Empire. Also, it will jack you up, as Kirk and the crew learned in "The Undiscovered Country."I'd imagine it's an allegory to things like Cuban Cigars being illegal in the United States. There's no real reason for it, it's a purely political motive on the part of the Federation.
Because it's blue.