In all seriousness, do atheists want to celebrate their lack of morality or moral guidelines?
Who said atheists lack morality or moral guidelines?
It's only true that atheism itself provides no moral guidelines. That doesn't mean that
atheists don't have moral guidelines.
It can be tricky, since there is such a wide disparity of opinion on the subject by atheists (everything from "morality is what we say it is" to "morality has a scientific and/or evolutionary basis") Is there any consensus?
The only universal consensus among atheists about
anything is that we don't believe that any god exists (which is necessarily true by the definition of "atheist"). There's not even a consensus as to whether or not we believe that no god exists.
Atheism is simply the lack of belief in a god. That's it. End of story.
Because atheism itself doesn't provide a set of moral guidelines, atheists get their morality from other sources, often from different brands of philosophy.
Since different atheist derive their morality by different means, you get a wide range of different answers.
But that's hardly surprising. Take a look at the many thousands of branches of Christianity. They all claim to get their morality from the same source, but there's still vast differences among different Christians as to what they consider moral and immoral behaviour. Ask different Christians about euthanasia, abortion, homosexuality, alcohol, or a wide range of other subjects, and you'll find that different Christians have different opinions.
Personally, I think that morality has a strong evolutionary basis. We're communal species, and tend to form communities for mutual benefit.
Throughout most of our evolutionary history we've tended to live in small tribes or communities. Since the success of the individuals in the community is often tied to the success of the community as a whole, and other people who share the same genes as us (our close relatives) are often dependant on the same community as we are, there's a strong selection pressure favouring behaviour that tends to be beneficial to the community.
So it's only natural that we tend to evolve instinctive inclinations to behave in a way that tends to be beneficial to the community. We call these inclinations "morality".
That list I posted earlier, I came up with that by considering what kind of behaviours would tend to be beneficial or detrimental to a community.
For example, the first one "
Do not cause avoidable harm, suffering or distress".
Since the community is made up of its members, harming the members also harms the community. Plus the community cannot function effectively if everyone is reluctant to interact with each-other for fear of being harmed or made to suffer.
(I won't bother going through the reasons for all of them.)
So while there may be large differences in the
specifics of what atheists (and theists) tend to regard as moral and immoral, everyone tends to agree on general principles, such as murder and theft being wrong, because we tend to reject any moral code which disagrees with our moral instincts.