I find it hard to believe parts of this statement. Yes, some teams started off as "office teams" but in order to compete they had to turn professional (pay players). There have always been investors in the bigger leagues. once you have investors, they always want to see profits in return.
The only way i can see a second division happening is the way it happened in England, but even then, I'd highly doubt the American investor would go for having thier $20million dollar team relegated to a league lower than what they initially signed up for.
Basically League 1 inherited clubs from another league. That other other league was considered division 2 and the current league 1 was division 1.
It would be like MLS buying USL and having that as Division 2 with MLS being Division 1. Other teams joined league 1 (Not sure if they just applied or if they had to pay to get in) and other divisions were created through folding leagues.