PhysX was BOUGHT and forcefully made exclusive. At best it is "NV bought game development program".
Then you slap another nice sum to bribe devs to use it, and, yay, it's sooo good for customers.
Just for the hell of it, let's use 100% reason.
Physx was exclusive before Nvidia bought it. You had to buy an Ageia Physx card to run it (that made it a hardware exclusive technology). Even then, Ageia had bought NovodeX, who had created the physics processing chip. They didn't do very well with their product. That was the issue, without Nvidia buying it, Physx, as devised by Ageia was going nowhere - dev's wouldn't code for it because few people bought the add on card. Great idea - zero market traction. Nvidia and ATI were looking at developing processing physics as well. So, Nvidia acquired Ageia instead to use it's tech and in doing so, push it to a far larger audience with, as
@HumanSmoke points out, a better gaming and marketing relationship with card owners and developers alike.
At best it is "NV bought game development program
Is logically false. NV bought Ageia - a company with a physical object to sell (IP rights). NV used their own game development program to help push Physx.
As far as bribing dev's - it's not about bribing dev's. You assist them financially to make a feature of a game that might help sell it. A dev wont use a feature unless it adds to the game. Arguably, Physx doesn't bring too much to the table anyway although in todays climate, particle modelling using physx and Async combined would be lovely.
All large companies will invest in smaller companies if it suits their business goal. So buying Ageia and allowing all relevant Nvidia cards to use it's IP was a great way to give access to Physx to a much larger audience, albeit Nvidia owners only. In the world of business you do not buy a company and then share your fruits with your competitor. Shareholders would not allow it. Nvidia and AMD/ATI are not charitable trusts - they are owned by shareholders who require payment of dividends. In a similar way to Nvidia holding Physx, each manufacturer also has it's own architecture specific IP's. They aren't going to help each other out.
Anyway, enough of reason. The biggest enemy of the PC race is the console developers and software publishing houses, not Nvidia. In fact, without Nvidia pushing and AMD reacting (and vice versa) - the PC industry would be down the pan. So whining about how evil Nvidia is does not reflect an accurate understanding of how strongly Nvidia is propping up PC gaming. Imagine if AMD stopped focusing on discrete GPU's and only worked on consoles? Imagine what would happen to the PC development then? Nvidia would have to fight harder to prove how much we need faster, stronger graphics.