Vampires Speak Wallachian

The Blade films portrayed a vampire language, which makes no sense. Why spent another night with some bald twat memorizing cases when you could be in a club getting your teeth wet? Why would vampires develop and sustain a vampire language when they could speak Wallachian?

Vampire: the Masquerade made no direct use of any vampire languages. Without Wallachian, the reader had to assume that elders spoke to each other in modern English, leaving them vulnerable to the nearest eavesdropper with Auspex.

When I say 'Wallachian', I really mean anything that functions as Wallachian. Any two vampires who know the language of a forgotten country would use it to communicate. And we have a complete soup of those languages.

Two vampires born near Constantinople around 1200 would speak some mostly-forgotten version of Romance-trash, a bastardization of Latin that no right-thinking monk or Muslim would have recorded. And just like Italian mafias in the USA in the 70's, the vampires could speak quickly, with their own jargon and 'cant', ensuring nobody had half a clue what they were speaking about.

Three vampires, born a century apart, around Hungary, Croatia, and France, would have less in common - but would probably know enough mangled Latin to chat, and to be minimally intelligible to anyone else.