Herd immunity is the process by which vulnerable people are protected by the rest of the population being immune, therefore preventing transmission of infections.
It is not, what is left when everyone who is vulnerable is dead.
Just be kind to each other in this hard time. Make sure those who are vulnerable around you are cared for. Don't hoard. Practice good handwashing. It is more important than ever, we take care of each other now.
No, the UK gov approach of "herd immunity" is pretty damn terrible and I for one am deeply critical and concerned by it.