It's absolutely facile to blame "British nationalism" - firstly, because it's not as if we're the only Western country to have problems, and secondly, well, as I said, it's totally facile.
The answer to your question "why are we not copying Asia" is, ultimately, people.
1) Experience: this vital component of the Asian response alas simply cannot be replicated. The region’s approach has been shaped by the traumatic memories of other recent epidemics — most notably Sars — which meant that governments were better prepared to react fast and forcefully and populations much more willing to co-operate. As I'm sure ours will be in future years and future pandemics.
2) Compliance: this relates to both experience as above, but also to the general political conditions of normal life. Chang Shan-chwen is convener of the expert advisory panel to the Central Epidemic Command Center, which manages Taipei’s response: “In [China’s] autocratic system, every citizen will stay at home when told so. But this is something which cannot be easily achieved in free and democratic countries.” Quite so.
Back in last March, Singapore banned short-term visitors from entering or transiting through Singapore, limited gatherings to 10 people, banned large events, and closed all bars and entertainment venues. Not so bad, right? We did similar (travel excepted). But they also enforced social distancing of 1 metre, and those who defied the order could be fined up to $10,000 Singapore dollars ($7,000 U.S.) or be arrested and face up to six months in jail. In some cases, both penalties were enforced. The government also used mobile apps, house visits and phone surveillance to monitor the activities of citizens and catch potential violators. Even in sainted NZ, the polis could search your home without a warrant.
Now you might weigh things up and think stuff like that is tolerable, and fair enough. I, though, do not feel admiration for autocratic, authoritarian states in general, and I certainly don't think that the extreme ends of the measures are justified or proportional, and in some cases, not something we should tolerate in any circumstances: it's the thin end of the wedge.
Doubtless you'll brand me a "pampered Westerner", or tell me I'm happy for my granny to die, but I don't care any more. It's how I feel. There's a degree of liberty I consider inviolate, as it is literally a foundation stone of the way we live whether there's a pandemic or not.