everyone (else) seems to be hating on atheists

[Annik]

The Big 5 personality factors are the standard for any sort of research on personality in psychology , backed up by a lot of empirical data. Its not really even under any serious debate other than the fact that it only gives a rough sketch of personality (with many subfactors which give a more complete picture).

So no, not just a "personality quiz".

The Big 5 is a personality quiz. You're asked to answer a bunch of questions and then they spit out the percentile in which your answers put you in each of the 5 categories. At best, it will give you a rough idea of what a person is like, however, you're missing something quite fundamental. We can't trust these tests are scientific fact. Why? People lie, even if they don't mean to or think they do.
http://en.wikipedia.org/wiki/Self-serving_bias
http://en.wikipedia.org/wiki/Actor%E2%80...t_concepts (particularly what is mentioned about why people think they do things)
http://en.wikipedia.org/wiki/Cognitive_bias

You can't trust what people say about themselves.