Not just a nice try-- plain facts.
the 20th century was the most secular century ever. It was easily the bloodiest as well.
Stalin and Mao killed over 100 million.
Atheism and Communism intertwined for a bloodlust that has gotten far too little examination.
Nietszche's Uberman left behind some bloody footprints in the previous century. I hope they never return.
Blaming atheism for any particular nutcase regime is as absurd as blaming theism for the inquisition or the genocide of the native Americans. Around 100 million were killed in a much less populated world, arguably making "it" the bloodiest period. Neither theists nor atheists ideologies are immune to their share of freaks.
One thing all those genocidal crack pots probably have in common is fanaticism like that posted here, imagining some other broad ideological classification is the root source of all their problems and no sacrifice of others is too high a price to pay to rid the world of it.