Herd immunity has never been an answer and to be fair, that isn't what the government is proposing.
We do have to get our economy restarted, I totally agree we cannot keep printing money and have the government paying the salaries of 50% of the population - as is currently the case.
There has to be a return to work for most sectors, whilst maintaining safety / social distancing as much as possible. It's too dangerous to reopen pubs, restaurants, cinemas or to stage large scale events though.
We cannot and will not have a herd immunity strategy, it is far too fking dangerous. The second wave of the virus, likely in Oct / Nov could be much more lethal than what we have already seen. It was in 1918.
What we will see is a controlled relaxing - and most likely tightening of the rules, so we can keep the economy going, whilst we buy time to find a vaccine.