I'm serious but I don't use gimp so what do I know. I'm posing it more as a theoretical question of why can't the collective we be asked to pay for features we want. What I know of Gimp is that it has majority of the features of PS so why would the power users not be willing to pay for advanced features that probably only they use. The answer in my mind is that they are willing to pay but they pay adobe because gimp doesn't ask for money.

You could avoid the bait-and-switch feeling if the non-implemented features were grayed out to distinguish them from the ones that were already available.