That logic may have made sense at the companies of old but companies today often present a Theseus' Ship dilemma for those working and wishing to jump ship.

If all of the engineers you work with move over to Company B and the leadership of Company A is recycled, what is left at Company A for you to be loyal to other than the name?

An idea or mission, I guess? Maybe a reputation? Good point, though

What's wrong with wanting to get paid? Do you think he should have been loyal to Apple?

Speaking as a startup guy, greater success (and happiness) comes from value generation than chasing bigger paychecks.