Art Briles been runnin spread since the mid 90s when he was a high school coach. High school coaches all over Texas started copying his offensive sets, then you started seeing it in college. Don't know who he got it from, but he used to dominate with it and put several qbs in D-I before becoming a college coach himself.
If a lot of teams ran the spread, you might end up with a different idea of the QB position. There are a lot more decent spread QB than you basic pro set or west coast offense because you don't need a 6'5" 240 lb qb with a rocket arm to run it. Perhaps you go with 4-5 QBs on your offense that are decent at running it and concentrate on getting the ball to playmakers rather than relying on 1 guy that gets paid $100 milly.