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

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

THE BIBLE IS THE PROBLEM!

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

Why does my vagina and around my butthole itch? I don't have weird discharge and I'm still a virgin.

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

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?

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

What one thing makes someone a very mature person?

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

A belief in a god is not 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.

What has been your best sexual experience?

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

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

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

I took a video of my serve (60 FPS) and it took 0.4 seconds from my racket to the service line. How fast would you say my serve was?

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