Agree we shouldn't just lob them in willy nilly, but I think there's a natural reluctance to blood youngsters generally (across all teams and even wider most sports)
How often has a new star emerged in an injury crisis when a club has no other option?
I'd say the incidence of new talent coming to the fore by this route is higher then youngsters being introduced in a "controlled way"
NB: I have no evidence to support this - purely gut feel!