General experience doesn't mean much since there are few standards. Ones experience would generally be used to take more responsibility, do more important things or in other ways advance ones career. Not as some measurement of quality, since that would be very subjective.
In a changing industry it would even be expected that when things change a certain amount of people won't last, because they get squeezed out between new people coming up and old people already specialized.
So while surely part of the industry focuses to much on youth I think people jump the conclusion that it is widespread too quickly.