What's frustrating about this is it was entirely predictable. The lessons from the HIV crisis and the drug war — as well as other long-standng public health concerns — made it clear that people would start taking risks sooner or later. https://www.washingtonpost.com/health/2020/11/12/covid-social-gatherings/
People gonna people. That's the ironclad rule of successful public health interventions. In this case, it meant that failure to get the pandemic under control quickly would lead inexorably to this point.
This situation, of course, has been compounded by many leadership failures, with Trump's being the worst but on all levels. Which means that responsibility for controlling the pandemic has fallen to ordinary people. And that's a disaster, because ordinary people are bad at this.
For one thing, the first instinct of most people to shape the behavior of others is to shame them: Call them stupid, reckless, selfish, etc. for socializing. I myself have that urge. The problem is shame is an incredibly ineffective way to get people to make better choices.
When people are shamed, they tend to focus their energies on mitigating the shame — not on making better choices. That often means shame backfires. For instance, studies show fat-shaming tends to cause overeating, probably to comfort yourself.
Shame can also cause people to double down in their defensiveness. It's just a really rotten tool for motivating better behavior. But it's become the major tool, because again, people gonna people, especially in the leadership vacuum we're facing.