This is a slippery slope. These policies had a vast affect on the lives of millions of people. Business were shut down. Schools were closed. People were instructed to stay in their homes for years. Simply saying, "Well, we made our best guess," is absolutely not acceptable. When the government curbs human rights, they have an obligation to weigh and justify the costs with scientific evidence.
What is your suggested approach when there is no (reliable) scientific evidence for any course of action and not enough time to gather such (reliable) evidence? Note that not taking any action is also a decision that, in your framework, requires supporting evidence.
Not taking action doesn't require supporting evidence, and insickness didn't propose a framework in which it does. There is at any moment an infinite number of things you could choose to not be doing. You can't collect evidence for not doing those things, as the amount of evidence required would also be infinite.
Not taking any action is also a decision, and it has to be justified like anything else that will affect the health and lives of millions of people.
You don't need to collect evidence for everything you choose not to be doing, all you need is evidence that the status quo is not worse than any other (known) alternative.
In any case, my point was that you can't make decisions based on evidence when you are faced with a new situation for which there is no (reliable) evidence. In these cases some other approach is needed.
