[AngelicaDeAlquezar]

@Babymetal: That's because "venir" is an intransitive verb and "acercar" is a transitive verb. While I can't perform the action of the verb "venir" on any object, I can actually make something/someone "acercar" something/someone else.

Same with verbs like "entrar", "salir", "existir", etc. Although you can put together something like "exísteme", the expression makes no sense, because you can't order anyone to exist on someone.

There is a difference with imperatives like "súbeme", "bájame", "llévame", which make sense because I can actually perform an action to shift a person from one place to another.