I won't generalize about IT departments, but many admins I've worked with certainly seem to be. For instance, I've frequently found Windows installations where Domain Admins is granted merely to allow a user to bounce a particular service, or to a service that needs write access to a few particular registry keys, because "that's the vendor-supported solution." Whether this vendor "support" extends to compensation for the cost of downtime caused by said overprivileged users accidentally installing untested "recommended" updates and rebooting a production server in the course of bouncing said service, or when a bug in the service causes it to recursively delete an unintentionally large portion of said registry, is left as an exercise.
More generally, I've found that admins seem overenthusiastic about learning about new features that vendors claim "increase security" or "reduce TCO", but are comparatively uninterested in creatively using existing features to the same ends, even when the former amounts to a monstrously complicated (i.e., because it must supportably generalize to thousands of diverse installations, not because vendors are stupid) configuration interface for the latter.
As for age, I'd say that, if anything, the problem is worse with younger admins who seem more inclined to take vendor claims at face value and assume that anything they might possibly need to know is a Google search or, at worst, a support request, away, otherwise the product is, as you say, "defective." Older admins seem to at least accept that any given component is but a part of a unique environment, and that they, not vendors, are responsible for ensuring the various parts interoperate correctly, even in an ostensibly "homogeneous" environment like a "Windows shop."
