This is not true at all. I’m fact, most of the Apple engineers I know online talk much more of politics than their work because one of those topics doesn’t have an NDA on it.
Apart from the gay CEO, shouldn't the Republicans be worshiping Apple? It's a trillion dollar company that has figured out a way to make software companies and developers to PAY THEM to create software on their platform (for the "privilege" of adding even more value to it), and then force themselves in between these developers and the users to further gauge out even more money from both its users and developers.
A really fine example of capitalism (academically speaking).
Which is increasingly important in the current political climate. Apple doesn't want their employees to be associated with any political views.