It's not features, it's workflow. Seriously. I can get more done with photoshop 7 than with a with a current spanky version of gimp simply because my fingers know what they are doing and the UI provides no surprises. Workflow is the king behind what people refer to as "features".
Can my fingers learn a new game? Sure. But it is harder to learn a similar game than one that is truly new, and there must be motivation present. It's a mental game, not a technical one. Putting the responsibility on me as a user to resolve workflow issues is what keeps Linux in the Desktop doghouse.
FWIW, yes, I still use Photoshop 7. t is one of 3 remaining windows apps that bind me to a dual-boot system. I use Gimp when I can, but in a pinch, it is often faster for me to boot into windows and Just Do It. I am willing to go the extra mile to learn a new interface, but not to sacrifice productivity if it is necessary for my job.
The Wright Bothers weren't the first to fly. They were just the first not to crash.