Apple may be worse than others.. but also know that people move around, and bring a part of their old culture to the new team. If they're in a senior position, and they have a bias towards people from their old employer while hiring, they could start hiring people from the ex-employer. Mix that in with a fast growing team, and now there is a risk of a subset of the company acting like they're at the old company.

FWIW, I have heard these types of stories before too, and they are definitely NOT unique to Apple.