They actually do. Their moral standards come primarily from the societies in which they reside. So, although they can't be a 'better/worse' atheist, they CAN be a better/worse human being.
Yeah, it's corny. No argument there. But, as stated previously, their morals come from the societies in which they reside. They can be judged by them.
Well, the fact that they aren't responsible for the deaths/suffering of nearly as many people in the 20th Century as the prior 2,000 years puts them more than a few rungs above Stalin and Mao. Also, their contributions to the collective knowledge of our species has been enormously beneficial.
A little criticism never hurt anyone.