I think your wife is wrong. I think it will encourage young people to either have house parties and not spend any money with businesses that are already desperate, or to go out and then invite other young people they meet in the pub back to their homes to carry on drinking. I think it's policy made by old people who think they know how young people behave.
Supposedly indoor gatherings of over 10 people are banned as well--likely to both prevent what you're mentioning, and to deter normal US Thanksgiving festivities.
And still, I don't see how it can be effective. The virus doesn't know what time it is.