This may seem kind of bizarre, and perhaps the criteria in many states need to be made clearer and more objective, but it's not an inconsistent position. In many contexts the law allows parents to expose their kids to different kinds of risks, but if the overall amount of risk is considered too high, then the parents' fitness may be questioned. In the alcohol context, a judge might consider that letting children drink at meals in their parents' presence was not unfit parenting, but knowingly allowing the children to drink every day without any supervision was.
This is true for several states.
My middle son turned 21 (legal drinking age here in the US) a couple of weeks ago. He never drank at all as a "kid." You couldn't give him a glass of wine at a holiday dinner, or a beer to watch a ball game or anything. Neither myself nor his mother were a part of his birthday celebration. I was honestly quite worried that he would be out with friends and have his first experience go horribly wrong. He has no idea how it will affect him. (Thankfully all turned out ok).
> Can an underage person possess and consume alcohol beverages on licensed premises?
> Yes. Persons under age 21 may possess and consume alcohol beverages if they are with their parents, guardians or spouses of legal drinking age; but this is at the discretion of the licensee. The licensed premise may choose to prohibit consumption and possession of alcohol beverages by underage persons.
But contrast it with Utah[1], Arizona[2], Kansas[3], North Dakota[4], Tennessee, Alabama, Florida, North Carolina, Tennessee, Indiana, West Virginia, Pennsylvania or Vermont.
[0] https://alcoholpolicy.niaaa.nih.gov/APIS_State_Profile.html?...
[1] https://alcoholpolicy.niaaa.nih.gov/APIS_State_Profile.html?...
[2] https://alcoholpolicy.niaaa.nih.gov/APIS_State_Profile.html?...
[3] https://alcoholpolicy.niaaa.nih.gov/APIS_State_Profile.html?...
[4] https://alcoholpolicy.niaaa.nih.gov/APIS_State_Profile.html?...
I grew up in Europe. I was planning on letting my kid try a small glass of wine with food in their early teens. But doing so in the US, I actually risk jail and loss of parental custody. Let that sink in...
The US has a really unhealthy attitude towards alcohol that results in binge drinking and excess in college, and society here almost prefers it that way which is depressing.
PS - I know many parents ignore these laws, but the point remains, the law makes no exception for parental consent or at home.