We see this behaviour in lots of industries. Car manufacturers will nerf the lower end vehicles so that there is more 'value' in purchasing a higher end car for enthusiasts.
And to hit a little more close to home - think of all the web companies doing exactly the same thing. There are usually 3 or 4 price points, each segment operating within the same code, but features enabled for the higher price points.
I see the same thing happening here. The 'performance' of the cards are the same after this hack, but the driver software 'lights up' exposing extra features. You could say the price differences pay for the driver features.
In the case of software as a service, different pricing tiers are at least semi-justifiable because you can argue that additional featuresets require more system resources to be added to the hardware infrastructure undergirding the site. If you want the more demanding features, you must compensate the provider for the extra infrastructure hit they'll be taking. Therefore, it doesn't feel as lame as intentionally performing a simple downgrade with the hope that you'll be able to trick others into paying more money for something that's already there if you know how to remove the foam/hack the resistor/whatever.
As far as more demanding resources go, that's not always the case but in a lot of them it would be. Think then about the various versions of Visual Studio or even Windows (Pro/Home) etc. The argument is still the same.
And with this nvidia case, the hardware hack only lights up new features in the drivers. It's exactly the same principle, and one others have shown is acceptable market practice.
Visual Studio and Windows aren't software as a service, and I suppose the argument in traditional client apps is that "the advanced features cost a lot more money to develop, so we need to recoup that cost". Neither case is as egregious as starting everything at a high-level baseline and then intentionally decreasing/damaging some parts to make them into "lower-end" models. Software is usually developed the opposite way -- you start at the baseline, get something together, and then say, "Oh, what about feature X? That'll take a while to develop..." and some guy says "Well, we can make it a premium feature". It just doesn't have the same feel as nvidia's hardware hack.
And to hit a little more close to home - think of all the web companies doing exactly the same thing. There are usually 3 or 4 price points, each segment operating within the same code, but features enabled for the higher price points.
I see the same thing happening here. The 'performance' of the cards are the same after this hack, but the driver software 'lights up' exposing extra features. You could say the price differences pay for the driver features.