No, not all atheists (or any other group of people) are arrogant and rude on Quora or any other platform. It is unfair and inaccurate to make such a broad generalization about any group based on the behavior of a few individuals.
Quora, like any other online platform, is composed of a diverse range of users with different beliefs, backgrounds, and personalities. While some atheists or members of any group might express themselves in a disrespectful or offensive manner, it does not mean that everyone who identifies as an atheist behaves the same way.
It's essential to treat individuals as unique and not judge an entire group based on the actions of a few. On Quora, just like in any other community, there are respectful and considerate individuals who engage in thoughtful discussions, regardless of their beliefs or non-beliefs. Respectful and constructive communication should always be encouraged in any online forum to foster productive and meaningful conversations.