Linear keyboard playing
AutoTonic is neither a piano playing hack nor does it take care of music theory for you. It is instead defined, by its patent, as a 'musical instrument'. It's a plain and simple interface converter, reinterpreting the control surface of any existing MIDI keyboard like a new device … to play linearly on white keys only!
Is AutoTonic cheating?
There exist all sort of instruments in the world. Wind instruments, fretted string instruments, whistles, bells, oscillator modulators, etc, and most of them are operated differently. So a trumpet has to be played in another way than let's say a chello, for example. While with both of these instruments you can play the same notes (not going into details with 'harmonic range' here), still, they're operated completely different from a player's perspective. Same with comparing AutoTonic to a traditional piano. They're not the same kind of instrument and they're operated differently.
"This is such a simple concept"
What does simple mean? Does simple mean stupid? Or doesn't it also stand for "unconstrained; natural; inartificial; straightforward"? Is key mapping a simple thing? There exists a so called 'harmony piano' which was officially used by Hadyn, Beethoven and Mozart …
„Johann Jakob Könnicke's Harmoniehammerflügel“ Credits: Photo © Kunsthistorisches Museum Wien
… it's one of the earliest approaches of linear key mapping and was developed over 200 years ago, at a point where even the conventional piano – as we know it today – was still not as established as it is now. The piano even at the moment of writing is still not that old, by the way, and there also existed many build variants, from different keys to inverted color schemes and knee-controlled sustain pedals etc, Today's (current) conventional piano layout is only one form of how a key-controlled instrument could be put into practice.
How can this not challenge your idea of what a piano should be? The piano as you know it didn't have to end up the way it did. Especially when having control over dynamic modality now with digitally controlled electronic devices (computers & MIDI keyboards), which are capable of filtering out unwanted notes so you can play expressively on a true linear arranged physical interface.