Why does it matter so much to atheists that God doesn't exist?

My problem is that people who try to shove their rules down everyone's throats - including by physical force - DO EXIST .

IT does not matter, mainly because it does not exist.

Notice that I said their rules, not any gods rules.

How would you spank me if I had been sent home from a school camp because of my poor behavior?

THE BIBLE IS THE PROBLEM!

I am speaking to the US Bible thumpers here, of course ~ many of whom are flat-earthers who deny evolution and see scientists as evil people who are constantly trying, and succeeding, in disproving their beliefs one by one.

Those rules that you are trying to reinstate are rules made by men who didn't know anything about the earth, nor anything about all of the other inhabitants of it. How can you not see that?

Why do some people dislike rap and hip hop music despite there being poor quality music in every genre?

A belief in a god is not the problem.

I do not personally care if you believe in a god or not.

And then use and ENJOY these fantastic scientific advancements every single day of your life?

A Revolutionary Drug for Extreme Hunger Offers Clues to Obesity’s Complexity - KFF Health News

Because these are not any gods rules we are talking about.

And how do you deny hundreds of years of advancement in all fields of science?

These are man made rules - made thousands of years ago for the use of the humans who lived thousands of years ago.

How do I convince flat earthers that the earth is round?

The people of the modern world have evolved past all of that nonsense.