The real story: When I first started working on the language, E, O, W, X, and Y were the only Latin letters I didn’t use in its orthography, so I thought it would be funny to make the name of the language out of those overlooked letters. (I’ve since started using W, X, and Y in the orthography as well, but that’s a different story.)
Those of you who know me know that I am not much in the way of a con-worlder. I create language, and sometimes just enough detail to make the language work, or make it funny, or make it strange. In this case, the in-world explanation for the name is that a team of linguists sent to study the language inquired about its speakers at a village near where they supposedly lived. This is maybe, vaguely, somewhere in China or Mongolia or eastern Russia (because that's how precise a con-worlder I am), and the linguists were only passably proficient in the local official language; furthermore, the inhabitants of the village they visited spoke a minority language that the researchers didn’t speak at all. So, through garbled second and third languages on both sides, they managed to communicate who they were looking for and find directions. The precise conversation is lost to history, but the researchers’ interpretation was this:
“Oh, yes, the people who live past that mountain. Go there [points]. They are called the Ox-Yew people.”
What the villager actually said:
“Why would you want to go see those people, past that mountain? [gestures] There’s nothing there but cows and trees.”