Spanish is a completely different language from English and there's absolutely no reason to follow its grammar. It's insulting to imply Spanish speakers couldn't come up with good ideas of gender neutrality. They/them are gender neutral pronouns, masculine forms in Spanish are not.

You're already coming from a mistaken place where you assume that this is only about creting a gender neutral term (which it is) but also a way feminists want to challenge the patriarchal assumption that the average person is a man. Or that women are de facto included when you're clearly addressing men. Language is more than just grammar, it changes. That you were told one thing in your class doesn't change the fact that its users need something else now.