There's also the problem I describe in this post on the culture of python-dev:
Telling someone "You're wrong, but explaining the real reasons why would require that I distil decades of experience down into a single email post and I don't feel like taking the time to do that right now, since even if I tried you would ignore me anyway" tends to be difficult to phrase politely.
I think there's also a strong element where things we've learned from experience are often hard to articulate in a way that adequately counters "But this time it's different!".
I know I didn't really learn the value of experience until a few years into my first full-time job, where I had a boss who was extremely smart, but not the best of communicators. There were quite a few conversations that ended with comments like "you know, in the time you've spent arguing with me about this, you could have implemented it the way I told you to".
However, despite that, I eventually came to really respect his judgement, because I worked for him long enough that there were multiple occasions where he turned out to be right and I turned out to be wrong (independent of whether I'd listened or not in the first place).
Coming back to the possible relationship to the entitlement of Gen Y (and maybe anyone when they're young)...
If you have too much of a Fixed Mindset, you probably undervalue experience. You likely think you have just as much ability to do a job as someone with far more hours notched up.
A Growth Mindset, on the other hand, celebrates building up experience over time. It encourages you that you don't need to be at the top-of-the-ladder from the get-go. There's nothing wrong with starting small and working your way up slowly.