I wouldn't think of a degree as a back up plan. But, chosen wisely, it can be a huge bonus within a pilots career. I won't bore people with the details, but if I were to look back at my career and cross off all the opportunities that I was able to take advantage of because of my degree there would be a lot missing. And incidentally, I'm not talking about having the piece of paper, but rather the knowledge and skills gained.
And I only got a 3rd - too busy arsing around in bulldogs!
A good solid technical education will never be wasted time in a technology dominated industry like aviation. You just need a career planning horizon that extends a bit further than 'get atpl - get rhs'.