The real reason why the NFL won't allow any more teams to operate under the Green Bay model is that as a community owned team, the Packers have to publish their financial details.
The NFL doesn't want that level of transparency and is more secretive than the CIA.
Take the city of St. Louis' lawsuit against the league for the Rams relocation. The settlement called for disclosure of finances to back up its claims. Instead the NFL just opted to stroke a cheque for over 700 million.
You can still be a season ticket holder without a PSL in some markets albeit in the 300s. If you want to remain a season ticket holder and refuse to hand billionaires your hard earned money, ask your ticket rep about available season ticket seats without a PSL.