You raise an interesting point. Since when did it become "expected" that parents would put their children through college? When I was growing up, kids worked part-time jobs to put aside money for college. Whether it was paper routes, bagging groceries at the local supermarket or washing dishes in a restaurant (I did all three), kids were expected to have jobs at a relatively young age. I've been working since I was 14 years old.
I also notice that many parents today (in addition to providing the college tuition) also feel compelled to buy their children automobiles, laptop computers and a whole host of other things that children with a part-time job could buy for themselves. No wonder they have nothing left for retirement!
There is nothing wrong with well-heeled parents telling their children that they should fund their own college education. I tell my own children that they should plan to take out student loans for at least half their college tuition. The other half, they should try to get through scholarships or money earned working part-time.
The child is likely to get a better education if he/she has a stake in it. Otherwise, the parents who insist on funding it themselves usually end up paying for 4 years of keg parties because the kids just aren't going to appreciate it.
I've been wondering that myself, and it only encourages immaturity on the parts of the adult children. I saw stark differences between those whose parents paid for school and those that did not when I was there.
Incidentally, in a number of states now (e.g. California) it is absolutely assumed that the parents will pay for school for the purposes of financial aid. The income and assets of your parents will be included in your own for the purposes of aid well into your 20s, whether or not you receive a dime from your parents. Which is pretty messed up, if you ask me.