Vos and Vosotros

The inclusion of "vosotros" and it's verb forms are pretty much ubiquitous in school and college texts regardless of whether it is taught in the class by the teacher.  This pronoun for the familiar plural you is part of everyday language in Spain but not the Americas. Over here we use "ustedes" for plural you, for both familiar and formal use.  I personally don't use it nor generally teach it, for pragmatic and personal reasons.   It makes more sense because our neighbors to the south don't and millions of them are here in our country, and I interact with them regularly and I identify with them as a speaker of Latin American Spanish.  Those that argue for the teaching of this pronoun say that it's part of the language.  Sure it is but by that logic, you must also say that so is "vos".  After all, "vosotors" means "vos y otros".  What's more, there are more speakers that use "vos" than "vosotros". I agree that a student who will travel to Spain or live there or who wants to read the Bible should become familiar with it.  But for the majority of the American students who take no more than the 4 courses of the basic language sequence, the usual motivation, notwithstanding taking the class for a requirement, is to hopefully learn to speak and understand.  Why?  While Spain is a popular destination, chances are that a student isn't looking to go live there or communicate only with Spaniards , but rather with the large population of Spanish-speakers in the US when he comes back.  Majors and minors are supposed to be familiar with the whole language (not just practical uses) and a variety of Spanish speaking cultures and so it should stand to reason, that "vos" and it's forms be taught to make the serious student's knowledge more complete.