To me the principle of “once untrustworthy, always restricted” sounds like the beginning of a new caste system. Everyone's children are going to make mistakes. The wealthy are going to be able to cover up their children's mistakes, the poor are going to be put on 'the list' and become 'restricted.' The restrictions will grow, and eventually you'll have a new group of 'untouchables'
Consider the restrictions that US law places on convicted felons. Millions of Americans have been stripped of constitutional rights, often for infractions as minor as stealing a coat or possessing half an ounce of marijuana. Felons often face considerable difficulties in finding employment and housing. "Once untrustworthy, always restricted" is a practical reality in the US.
I understand the US isn't perfect, but I feel the real effects of comments such as yours do as much to excuse China's brand new system as they do to bring light to flaws in the US's system.
I think it must be emphasized that "once untrustworthy, always restricted" is a new policy in China that's being implemented, while in the US it is a historical principle that's coming under increased skepticism and criticism.