The UK is not the only country with a 10pm curfew but it is the only country with idiots doing that. You can't blame the government for everything.
What's the explanation for it? I can't imagine you'd find much evidence that there are more "idiots" in the UK in a general sense than most comparable nations, so what's leading to such different behaviour?
I don't blame the government necessarily, but it doesn't seem a big leap to think it's directly related to the confused messaging from the government. How many other countries have an incident like Boris Johnson and his "I shake everyone's hands" at any point in the pandemic, never mind right at the beginning? I imagine every country has had some public official skipping out on lockdown measures briefly, but that brazen attitude combined with his comments at the time seemed pretty unique. That was quickly followed by the UK government explicitly following a different approach to its neighbours in the early stages, only to flip flop and demonstrably pay for it.
Maybe every country has an equal number of people that look for an excuse to exploit those inconsistencies, "misunderstandings" and whatnot, and the UK just happened to hand it to them? As time goes on, adherence is going to slip for everyone, decades of research on all kinds of adherence to personal and public health measures show that, and all you need is those two things combined to get these examples.
Edit: I'd add that I've got friends in Spain and Germany who suggest big parties are much more common there than in the UK at the moment, it just isn't getting the same intention because there's not the same kind of generational in-fighting and blame games, and the climate and areas make it easier to do this further out of cities. And there's been reports from locals in here of music festivals and the rest going ahead as relatively normal in their countries. Very few examples of young people across the globe managing to reject that need for large social group connection. It is socially programmed into them in a way it isn't for older generations, given education structures and the culture that built around them.