I don't fully agree, but I know hardly anything about the mechanics of the piano, so perhapps I'm just talking nonsense here, but bare with me. As I understand, the hammer at some point of it's journey to the string is supposed to be set "loose" from the key, and keep moving with it's inertia until it hits the string. Now, if the hammer hits the felt strip before it is let loose, then the touch should feel very different indeed, and not only the sound. This is what I think of why playing with the practice pedal feels so different. Let me remind you, I'm just guessing here.
On the other hand, I agree with your signature completely. Instrumentalists are all wannabe singers. Wind instruments are the most obvious examples of this. They let you sing through the instrument. The rest, are basically the same thing.