What would you update them to? Secular philosophy has zero consensus on the most basic ethical questions after trying for 2500 years.
And yes, we are applying ours current to the times. You know this. You just lie and claim we don't, and only you are advocating "1.0" for the schizophrenic purposes of attacking them. Which, is odd, since 100% of the norms you have you got from theism by cultural assimilation, which you then deny the source of, and you have no defensible objective source of your own. Atheism never has come up with anything of it's own, never will, and frankly, that's exactly what you want. You'd no more follow a non-Christian set of ethics than you would a Christian one. You want your moral code to be synonymous with whatever your whims are at the moment. I'll believe otherwise as soon as a concerted attempt is made to come up with... anything, as an alternative.
Religion, also, assimilated from other sources, and humans have, over the aeons, developed their ability, whether that individual belonged to a religion or not.
The religious often like to say that their reason led them religion, so you see, our ability to see the value in some moral teaching, is linked to our capacity to reason. And our capacity to reason has slowly developed, and it has developed over a much longer timespan, it actually predates the major religions. That's where our morality "comes from". It all arose together, and so I don't think you can just separate one area (religion) from the rest of society and claim that it was only religion which drove things.
Consider, I can't actually feel the pain another person feels, especially if they are living on the other side of the world and I have never met them. But I can perform a cognitive trick, and I can ask myself rationally, "If I was them, would I be suffering?"
That's the Golden Rule, and it is very old rule. The key is that it relies on our ability to rationally ask a question which then leads to an imaginary leap of empathy.
I can't feel what it is like to be that person, in their shoes, but I can rationally pose the question, and then consciously bring it up in my imagination, to try to see a story, about what I might be feeling if I was that other person. Cognition is key.
And cognition is hard. Over time we gradually learnt to apply that rule to more people. We didn't used to apply it to slaves, you know, the slaves who had very religious owners. Did religion stop slavery? Doesn't look like it. No, we gradually applied the golden rule, rationally, to more and more situations. Today we use it even when imaging the biosphere.
So atheists, insofar as they have a brain, can very well think about morality and ethics and come up with answers, and our answers today are better than the typical answer you got 2000 years ago. Which isn't to say that a Buddha or a Jesus or a Lao Tzu couldn't still best us today, but they were ahead of their time.
Of course, thinking rationally about ethical problems, is hard. It is hard to try to act in the interests of the whole world. And so people can and do disagree. But that doesn't mean it is hopelessly relative and self-indulgent. Humanity is gradually pulling itself up to become better. Now, this doesn't preclude an afterlife and so on, but we have almost NO evidence for such, and all the major religions disagree on this anyway, some say you have original sin, some say you have your previous karma, some say you can be saved, some say you can only save yourself, and so on, so until we get some real evidence, we are simply having to make do with not knowing.
And that's ok, because maybe, if you wonder that there is more to life, maybe us not knowing is part of the situation, and you'll be tested at the end, and maybe they'll ask, so what did you think of the golden rule, did you use it much?