Why!? People die. It is a natural occurrence.
Duh, death is a natural occurrence.
But excess mortality is not normal. And the scale of excess mortality, partly avoidable, is certainly not normal.
Very infectious, but low mortality.
Tell that to the families of the 255,909 (at the time of writing) Covid-19 deaths in the U.S.A.
And it also makes victims in other ways, for example by reducing people's health/productivity for the rest of their lives, or by making it impossible for other elective procedures to take place.
Hard to prevent, easy only to postpone and prolong the misery.
???
It is not difficult to prevent, but most of us are not willing to bear the consequences of its complete prevention. Hence the need to keep the pandemic under control, by buying some time and reducing the pressure on hospitals until there is a vaccine or drug. Not controlling it borders on criminal behavior.