You're assuming the company is compensating and allowing people to work their way up. The new way of doing things in big companies is to care less for training, make people do that in their own time, then not give them compensation in accordance with their new skillsets. Loyalty flows two ways, it's something I've learned in tech over the last 10 years, and in general, companies over 50 or so people, don't have loyalty, only profit margins.