There seems to me to be an overreaction to this virus over other known health crisis, and for that matter other emergencies simply do to the unknown / novel nature of this event.
The other problem with your response is the pure assumption that a total lockdown of all citizens was the only option, and that anyone daring to suggest there may have been another more measured way is simply wanting to put "leisure activities" over peoples lives, the fact remains that several people have suggested alternative measures that could have been used, including isolated only those of the vulnerable population where more than 80% of the deaths are accounted for, and where outside of that vernable population COVID is less deadly than the normal flu. Do you propose these same lockdowns every flu season? after all the flu does cause "mass death" as you seem to define it every year so it must be a reasonable response to shut down the economy every flu season right?
You do understand that the lockdowns where never to prevent the transmission of the virus, but rather simply slow the rate of transmission to allow the health system to sick and not be overwhelmed.
I will not bother to address your reductio ad absurdum on radio active material as it holds no bearing on this conversation, but I will say my position on that would not be what you expect :)
>>For some unknown reason you believe these lock downs are unreasonable, without any clear rationale.
Well allow me to provide some Rationale then
1. There were / are viable less extreme measures that could have been taken
2. It is yet to be seen if the Lock Downs actually were effective, there is some data to suggest they were not, and simply stating "it would have been worse" is not evidence based. Some data suggests that COVID was already widely spread before the lockdowns even went into effect and a large part of the population was asymptotic or suffers very mild symptoms
3. There is no section of the federal or any state constitution I am aware of that reads "These rights can be suspended in a time of emergency" while I am aware that the courts have played mental gymnastics to carve out these exceptions, the fact remains these acts prove the constitution is powerless to prevent infringement of basic rights by government
4. The precedent set by these unprecedented orders will be used to infringe on rights of the population using thinner and thinner justifications for an "emergency", I can see a flu season being used to trigger a draconian response in a few years.
5. One of the bigger problems I have with the lock downs is the open ended nature of them, and the power to extend or lift them is in a single person, in a single branch of government with out limit, oversight or control. It may be needed for a governor to act quickly to get process started, but that should then need to be follow up with some other branch of government oversight no less than 30 days after a governor acts. This is not a dictatorship and we should not devolve into one in a crisis