Did we play right into Bin Ladens hands?

I guess an appropriate answer would depend on the point of our reaction to 9/11. If the point was to stop terror attacks, then you are arguing in your own question that we have provided inherent deterrents for another attack. If the point was to defeat Bin Laden, that could also be argued a success since he has been marginalized. Just like Obi Wan Kenobi, striking him down could have just made him more powerful than we could have possibly imagined.