My theory is there is a certain set of people for whom everything came to them easily and have never really faced financial adversity (or overcame it wildly with some nice breaks and a little hard work), therefore they believe that will be the case for their children automatically as well. An assumption that no medical issues will ever arise, and that other people will always be willing to just invest in your business idea, or whatever. Those of us that understand life can be hard and cruel tend to have the opposite view, and want to help our children have as much of a leg up as we can help them get, because there's a good chance life will knock you down mercilessly.
I haven't done the analysis on this yet, but part of me wonders if we might one day find a division along these lines to some extent between extroverts and introverts (strictly those that have the $ to leave I mean of course). Life comes easily for extroverts in terms of the career part at least, and they are the salesmen that can easily just convince people to give them money. For introverts, the corporate world is stacked against them and promotions are nearly impossible to attain, and they have to claw for every inch. Might be totally off on this, but it does make one wonder if introverts are more likely to want to help their kids out.