There's plenty of evidence in WC that mankind in 600 years is exactly the same as it is today. Heck, right until the Kilrathi war, Confed is busy pushing anti-Pilgrim rhetoric, while the Pilgrims do vice-versa - and both are human. Indeed, by the time the Kilrathi wiped out the Shata, Confed had already fought its first interstellar war. What happened to the never-again-heard-of Yan? Did they just... disappear? Or is it that they were - dare I say it? - exterminated, exactly like the Shata? There have been plenty of cultures in human history which seem to us today to be pure evil. Yet, to judge the entire race based on the actions of just these cultures would be wrong, if not downright stupid. Similarly, it is wrong to judge the Kilrathi based on what little we know of their culture and history. You may disagree, and point to how many different races they've wiped out in the four hundred years leading up to WC. But the only reason the humans didn't subjugate (sure - 'subjugate' may be considered better than 'wipe out' by some, but the truth is both are equally despicable) so many races during this time is because they were too busy fighting each other. No. The Kilrathi have done a lot of bad things, but so have humans. I suppose it may be that both are evil, but that's not a particularly appealing idea.