Simply because you won't know where to stop.
After the disabled children, who next? The not-so-bright? After that the ugly and then later the rude and finally the poor?
Will we be left with only the children of the rich and powerful? Who then will be available to work in their restaurants?
The answer to this issue is not that difficult.
Parents have a basic responsibility to their children and adult children have a basic responsibility to their parents.
Basic responsibility usually means food, shelter, safety, healthcare, education and a proper upbringing for the former; food, shelter, safety, healthcare and at least a similar lifestyle to what they themselves have for the latter.
Public policy is to make sure people carry out their basic responsibilities and have the laws in place if necessary. Reinforce the legislation with education. Basic responsibilities does not mean latest gadgets always for the spoilt brats and abalone and bird's nest every week for the spoilt old fogeys. You do hear of both types demanding these from their overworked parents and adult children.
And unfortunately, if it's proven that either the parents or children are unable (NOT unwilling) to carry out their basic responsibilites, then the state has to pick up the slack, although those with pappy mentality will tell you otherwise.
These are all basic responsibilities of a decent human being and a decent country.
