Please tell me, how tree service is essential business when people had ZERO tree damage or old tree need to go?

Tree Surgeons work alone outdoors, they cannot infect anyone. They are trying to make a living.

With some experience in arboriculture, I can't really comment without knowing the history of the tree; I would have thought if the work could be readily accomplished without infecting anyone there would not be an issue. Trees do become unsafe and do need work and life goes on. 

We just had several days of major wind.

And, people outside of your immediate neighborhood may have had wind, too.