The airlines don't care what your degree is in. Having a degree simply shows the ability to succeed in an academic enviornment and maybe shows a certain maturity in completing the goal. A non-aviation degree in a second area of interest is a good fall back and also might help you pursue something else in your spare time down the road, if you desire. If a person has no second area of interest, then an aviation degree is fine, but there is nothing you'll learn from it, or take away from it, that you're not going get somewhere along the line in your flight training or airline ground school, or just from reading a book.