Don't know how many plan on majoring in engineering. (I saw a web site stat some place with those numbers, but I can't remember where). But I can tell you that for the academy/air force, it's a non-issue. Just like they wanted a "Well Rounded" kid out of high-school coming to the academy; they want a well rounded officer corp in the air force. Put it this way; if majoring in engineering was preferred by the academy, they wouldn't offer so many different degrees.
And for those who are new and haven't asked yet, NO, you don't need an engineering degree to be a pilot. You can have a degree in behavior science, history, or any other degree available. Yes, if you want to be a test pilot or nasa astronaut some day, an engineering degree would benefit you, but not to be an F-15 or C-17 pilot. And there are some other post academy degrees that require certain classes and prefer certain degrees, (med school), but generally speaking, you can get a degree in anything just about you please. And many people do. Yes, engineering degrees are popular, but it's not all there is. Best of luck. Mike....