That's the problem. If you want to make something that isn't piano like, you run right into a brick wall -- there's no way to send the note information you wan

That's the problem. If you want to make something that isn't piano like, you run right into a brick wall -- there's no way to send the note information you want to send in a way that's understood by any random MIDI synth. That makes it much more difficult to be successful. Recently expressive instrument makers have settled on MPE as a workaround. That works, but it's kind of kludgy and isn't widely supported. You can also use an MPE-like approach on synths that don't explicitly support it as long as they're multitimbral. Unfortunately there's a lot of amazing synths out there that aren't multitimbral. Recent controllers that use MPE include the Linnstrument, the Roli Seaboard, the Haken Continuum, the Expressive E Osmose, and the NuRad wind controller.