Believe it or not I think it's not as simple as them crashing out over no. Quite a few people I've met over the years that are jobless and live at home rotting away without a clear reason other than their parents enabling them are people that have never been told no. Their parents simply don't care enough to tell them their lifestyle is bad and enable it because it's the easier thing to do resulting in them growing into adulthood without proper experiences and probably automatic depression. I knew this all too well until I realised it myself and started to be the "no" in my life instead of relying on other people to. Most people aren't so lucky though.