Nope, never considered quitting.
However, I think that first big major crash changes things for a lot of people. If it happens to you, things suddenly become a lot more serious when it comes to being smart and taking care of yourself.
Before my first big injury I never hit the gym and I took a lot of risks that I didn't need to take.
After my first surgery I started working on regularly and I try to be smarter about which risks I take and how I can limit my risk while learning.
If you love snowboarding, the big crashes and injuries won't stop you, instead they'll make you a smarter, safer rider.