If you notice, I didn't call for a ban on atheist beliefs, which would be possible to enforce; I called for a ban on public dissemination of atheism or the atheist agenda. Just like we have against the dissemination of child porn, and for the same reason. Atheism is even more destructive to souls than child pornography.
Remember, the ultimate goal of mankind is to get as many souls into heaven as possible, and so any measure that furthers that goal is inherently good and just, and should be used.