Think about hang drums, diatonic harmonicas, or about the Tenori-on. They make it basically impossible to play a "wrong" note. But a normal piano was already a step in this direction.
A piano restricts the pitches to discrete ones, making it harder to play a "wrong" pitch. Violins, and to some extent, guitars, have continuous pitches. And there are indeeded some pitch nuances that piano players can at best hope to hear (e.g C# vs Db), and some pitch effects that a piano player can only mimic (glissando, vibrato).
However, nobody today would argue that a piano player isn't really "playing music".
> this could potentially be used to bring people into music that normally would be too intimidated to consider it
And this is where the real issue lies IMHO: playing or making music shouldn't be "intimidating", but the way we teach it certainly doesn't help.