Board Thread:Warhammer 40k General Discussion/@comment-9026161-20130719005722/@comment-3258762-20131013103329

I would also like to point out that, according to Lexicanum, the Tau USED to be the Good Guys of 40k, but that fans didn't think they fit in (For good reason) in the Grimdark, thus leading to GW and it's sister-companies making them more fitting for the setting, by, and I quote lexicanum "...the mind-control powers of the Ethereals and their habit of exterminating conquered populations that stubbornly refuse to integrate into the Greater Good."

This is fitting, in my opinion, the Tau can very well be the least evil of 40k, but they should not be good. Good does not fit in 40k, Good looses in the Grimdark setting, they don't fit in if they are so nice to everyone.