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!

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

What happened to everybody's thick skin? It used to be that people really didn't get offended, now however, everybody gets offended by the least little thing.

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

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

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

What sexual experience did you have at a highway rest area?

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?

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

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

'Materialists': Celine Song on Dating and Sex and the City's Influence - IndieWire

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

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.

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

Why are Republican politicians so afraid to oppose Trump?

A belief in a god is not the problem.