Make it sense... if hell isn't real to atheists, why do they react so strongly?

I've noticed this a lot on social media during religious debates. What genuinely confuses me is why Atheists react so strongly and see it as a major issue when religions teach that non-believers face eternal punishment for not believing.

It makes no sense? They don't even believe in hell so why do they react so strong when people speak about the outcome of Atheist? From what I see online, their reaction seems inconsistent. If hell doesn't exist to them, then a religious person talking about hell should be meaningless to them just words about something they reject entirely. Yet they act extremely and emotionally offended. That suggests their real issue is with the very idea that there is an absolute truth about right and wrong something they totally reject because they have no foundation for it. I mean Atheism don't offer morals.

And where do atheists even get their morals? It seems to me they borrow them from religious traditions while rejecting the source. Without religion, they have no foundation for right and wrong except what society taught them, which originally came from religion anyway.

That's what I honestly don't understand.