Universal Translator?
Oh you mean that thing that I choose to ignore the existence of?
In all seriousness: Having a device that can translate EVERY language would be absolutely silly, since most planets would develop a lingua franca before moving on to space colonization. It would make little sense for a translator to know more than each planet's main trading language.
I just headcanon that learning the language of other species is required to travel through space, especially since the Ramen Chef on the Citadel uses occasional Japanese phrases, like Itadakimasu, which means "Let's Eat!"