LOL
They play 16 games now over 17 weeks and 4 pre season pseudo scrimmages in August, as they work back through training camp, during which starters play about 5 quarters spread over 4 weeks. Starters would now have to play those 5 quarters within a 2 week pre season to get them ready to then immediately commence 18 more regular season games over 20 weeks with the goal of playing 23-24 games over 25 weeks. Meanwhile it would have also made it exponentially more difficult for coaching staffs to figure out how to fill out the expanded rosters with high functioning backups and identify functional increased injury depth absent sufficient game reps for evaluation of non starters in pre season...
Every team would lose at least three weeks of off season recovery or conditioning time, not to mention coaches would see their time for evaluating performance of present players, potential FA's, and potential draftees shrink by 1/3rd. Even BB has acknowledged the effect that has on a perrenial playoff team over time under the present system. Now all teams would be on that schedule and playoff teams would be stretched even further.
But other than that, it's obviously a no brainer...
I'm guessing that's why it seems so simple to you.