The real question is why? I don't think becoming a pro is hard if you ride enough, but the real question is why do you want to be a pro?
If it's for the ability to snowboard a lot, then forget it because you end up riding for other people and having less free time to snowboard the 'bigger' a pro you become.
If it's for the money then forget it because most pros don't even earn enough to pay rent and have to work a second job while living paycheck to paycheck.
The only reason you might want to be a pro is if you love competing. Everything else about being a pro is overrated, generally sucks and can be found in far better careers and jobs.
For example, I know several people on this forum who get paid more than most pros, while snowboarding more than most pros, and have better job security and freedom to do what they want compared to most pro snowboarders.