Atheism isn’t a religion. It wishes it could be a religion. But it’s not, so it’s doomed to reinvent everything religion already does, badly.
Atheist dogma is based on the religious concept of God. They couldn’t make up their own concept, because they just don’t have the time to sit around and get on the same page. So the whole thing is based on the denial of someone else’s concept.
Atheist values are simply the values of the larger culture that the atheists were born into. For most that’s Christianity. Christian values of tolerance, redemption, acceptance, forgiveness, brotherly love, atheists hold in the same way that Christians do, because that’s what the culture is. When atheists raise children, they inculcate the same Christian values their parents had, just re-envisioned with a different set of beliefs.
Atheists for the large part don’t bother with making new traditions. A few sects like Pastafarianism have, but it’s not the norm. Most Christian atheists celebrate Christmas with their families. I would put dollars to donuts that when atheists are the heads of the family and finally find themselves in the position of having to create lasting traditions to keep their families together, most of them are going to just lose the attitude and just gather everyone together at Christmas just like their parents and grandparents did.
In fact, typically the only thing that really distinguishes atheists from the religion of the family they were born into is belief. Which is a really only a tiny part of religion. Without being willing and prepared to do all the work it requires to separate their values, culture, traditions, and dogmas from the monotheistic religions they’re supposedly getting away from, it’s going to forever be perfectly fine to see atheists as simply wayward children, rebellious teenagers.
Because the traditions, values, culture, and beliefs of Christianity aren’t broken, they work just fine for what they are intended for, knitting the fabric of families and society together. Atheism isn’t a religion simply because it doesn’t have any thread to to do that with. Atheism is anti-thread.