I never said they wouldn't exist. They won't be as popular simply because the physical interface will not be designed specifically for any particular software.

Look at the midi keyboard controllers. See all of those knobs, buttons and sliders. Which ones will control the simple ON,OFF, FILL A, FILL B, ETC. functions? Now how do you control chord recognition? By screen menu, button, switch?

A generic keyboard matched with multiple software programs give you just what we have now, an interfacing mess with little or no tactile satisfaction. Even arranger modules like the Ketron and Korg aren't as popular as their keyboard cousins simply because of the interfacing, distance, tactile problems.