Actually, there IS a distinct rise in narcissistic traits in the generations post-X.
That's documented. Now, does that correlate with anything else that can be documented?
Who knows, right? Mechanism, mechanism, correlation fallacy and all that.
But the fact that young adults are facing terrible job prospects has probably not a lot to do with it either way. The ground HAS changed under them, though whining and entitlement probably isn't serving them well (as a demographic) in light of that set of facts.
Perfect storm, perhaps?