It is basic triage...take care of the thing that is most likely to kill you immediately, and then try to worry about the other stuff later. The other effects of the lockdown are more likely to have there impacts years down the road, and we can always hope we can find other ways to head those off before then.
I agree with your basic premise that we need to have a more rational discussion of the costs of our preventative measures. I have said from the start, and I stand by this: a conservative approach is wise when there are so many unknowns. But as we have a better handle on exactly what we are dealing with, we need to start having tough conversations.
Some want to frame it as "lives" vs, "economy", but that is an over-simplified ploy to try to win an argument based upon people's emotions. The economy and our ways of life greatly influence health, so it is really "lives if we go this route" vs. "lives if we go this other route." The tough part is that no matter which way you choose, some will end up with the short-end of the stick, and that sucks. But that is the reality when you are trying to decide not just what is best for 1 person, but what is best for 330 million people.