I had the natural distaste for simplified alien races before, but I've mellowed slightly in the belief that it is very difficult to get across the complexities of a culture within the confines of one small story.

The idea of aliens serving the purpose of relfecting humanity, rather than simply being characters in their own right, is also something I considered.

Of course, one of the many things I love about the Zentradi is that the simplicity of their race is a plot point, and treated as a burden rather than a natural state of affairs.