I realize you're all trying to have a serious conversation about K'kree. I won't add any jokes but I will try to explain what the joking is all about.
Yes, "militant herbivores" does come across as an oxymoron to many people. Hence it's a set up for jokes. It's hard for people to picture a herd of cows running around with guns. "Far Side" comics instantly spring to mind.
Another factor involved, is that humor helps people conquer fear. Given how everyone here agrees that the K'kree display some truly horrendous qualities (no qualms about genocide for instance), it is not surprising that people would want to make fun of them. By picturing K'kree as BBQ fare, they ability to inspire fear is reduced.
As a historical example, think about all of the racist jokes and cartoons targetted at the Japanese during WW2. While ugly and base, by making fun of the Japanese in this crass way, it helped American G.I.'s overcome their fear of an enemy who all but obliterated the American Pacific Fleet at Pearl Harbor.
Now with my psychoanalysis complete, those of you who aren't part of the
Bearers of the Flame playtest will be interested to know that the K'kree play a major part in the history of Charted Space between 1202 - 1248. I'm not sure what's exactly public knowledge, but I believe that it's safe for me to say that the K'kree are part of the
Dominate, a post-Rebellion faction striving to make Charted Space theirs alone. While this conflict is resolved by 1248, the Dominate is by no means vanquished. Of course, there's no reason why a GM couldn't make his players
play through the Dominate War.