If anything, a degree gives you another 3 years to learn a little more about how the world operates, while at the same time having loads of fun and drinking plenty of p*ss.
I would have hated to go looking for my first flying job at age 18/19. I personally don't think I would have been ready for it, and I dare say a lot of employers would feel the same.
I did a degree in aviation, simply because I know that even if I can't fly for a living, I definitely want to be involved in this industry. Maybe it is a little specialised, but that doesn't bother me in the slightest.
Cheers,
TL