Everyone has a different definition of what makes a campaign good or bad. In the case of the OP, that seems to hinge on the amount of rules made legal in the campaign, and that's fair. But Pathfinder Society is growing at an exponential rate, and much of that growth is likely due to people who want to play a ninja or magus or even a synthestist-archetype summoner having the ability to do so.
We at Paizo put tens of thousands of dollars and hundreds of man-hours into every book we produce. Restricting those options from the largest body of players doesn't make a lot of sense from a business perspective, and we'll continue to make as much content available for those who want to use it as we can without sacrificing the flavor of the campaign.
As to how we plan to avoid the "mistakes" of other organized play programs, our editorial department includes former administrators of three different iterations of Wizards of the Coast's comparable programs (Living City, Living Greyhawk, and Living Forgotten Realms/Encounters) and we don't shy away from discussing what worked and didn't work in those campaigns. What some may view as mistakes, however, we see as simply different decisions, and clearly decisions we make can be viewed as mistakes just as easily as those made by other game companies.
Organized play isn't for everyone, and if a player prefers a more rigid grasp on what is and isn't possible to encounter at his or her table, it likely isn't the environment for that player. But we have a thriving message board community on paizo.com and Campaign Coordinator Mike Brock and I read every post on threads therein. So if the OP really feels any decision we have made signals the death knell of the campaign, by all means, raise that issue on the Paizo message boards and we'll gladly host a conversation on it where we can see the path the discussion takes much easier than we can on ENworld.