I don't enjoy either of the directors you mentioned in regards to the "younger generation", but I don't really enjoy any of the actors you mentioned as great either because I'm 24 years old. I don't enjoy movies from 30-50 years ago that actors like O'Toole starred in no matter how good of actors they were, but I do enjoy movies like Lawless and Fury that Shai starred in.
Haha no, I'm just noting the difference in tastes based off age groups.
I don't think it's a function of age group. Talent is talent. That's why Brando, Cat Hepburn, Newman and O'Toole are still regarded as greats decades after they were relevant. What changes over time is the ability to recognize talent.
With studios churning out tripe based on YA novels to turn a quick buck, and Michael Bay and James Cameron seemingly trying to convince the world that quick cuts, incomprehensible actions scenes, and CGI budgets that rival the GDP of many nations are "freakin' awesome," I'm afraid the younger generation might not ever know what great acting is.