Why are some Atheists so rude and arrogant?

Atheists have one thing in common- a lack of belief in a god/gods. Stop stereotyping people- you are being rude. You might not force your beliefs on others and I respect you for that. However, if you consider yourself a member of a group (hypothetical as I don't know what religion you are) that has misogynistic, phobic and generally ignorant views I would find it difficult to respect you. If any other group insulted large sections of society and attempted to prevent them from having basic human rights they would be chastised- just because the group has some religious affiliation isn't going to change my opinion.