Because 10.01 pm is so much more risky. The logic isn't there. Staying for one hour is no more risky from 7 to 8 than it is from 10 to 11. Staying from 10am to 10pm might be a bit off though. In my experience mingling ain't a big thing either. You meet your social group, pick a table, and then stay with them. Only if you go to the bar to order do you get close to others, and that's not necessary any more because you can order from your table and the server will bring your covid directly to you.