I would disagree with that. Complex rhythms require corresponding notation. You can only dumb it down so much. Don't get me wrong, I think your idea is good for simple tunes, but doesn't really scale up to playing more interesting music. Plus, I'm a good typist, know the keyboard, but I found it difficult to read the Musitude notation, and automatically hit the right keys. And the user will always be limited to what's written in the Musitude library, unless you have a facility to generate the notation from what the user types in at the keyboard.
This is going to seem like a rant, but what the hell.. we seem to be increasingly obsessed as a society, with putting in minimal effort to achieve things. Take app development - there was a guy on here recently who was wanting to create an app, with no coding. It's not possible. And it's not possible to become a competent musician without first learning the basics, like how to read music, and mastering an instrument. Plus, learning to play something properly, and getting better, is a very satisfying experience. It's about the journey, and putting in some effort to achieve your goals. These days people just seem to demand things instantly.
Again, nothing against your app, I think you've done a good job, and best of luck with it.
I still think you don't understand music.
I can probably take a guess and assume you are already a musician on some level who can read music and play an instrument and people who are proficient in something can sometimes lack an understanding of the basics of it. That's why the very vest a things often don't make good teachers of it.
But I would say it's a logical fallacy to confuse the journey with the destination. whatever level some musician is on, it's the joy they feel when they play pieces that is the objective not the right to say they suffered and struggled to get there so they 'deserve' to feel that joy due to the sacrifice.
A few hundred years ago buildings were constructed entirely by hand. Is a modern building not qualified to be called a building because technology made it easier to build? Or do late 19th century settlers in California have less legitimacy because they made the journey from the East coast by train rather than walk or ride as earlier settlers did?
Also, you are confusing the concepts of 'dumbing' down and 'simplifying'. They are not the same.
A lot of people have the same issue and the confuse the principles of music with the western notation and instruments and they conclude that if it isn't express in western notation and played on an existing instrument then it's not valid.
Notes are just symbols, the symbols can be anything as long as they adhere to the principles of music theory. And in principle there is zero difference between a key layout on a piano and on a qwerty. In fact accordions have a similar layout to a qwerty.
As I said, you haven't seen the full notation yet. And also, some instruments are more flexible than others. A clarinet can't play chords and there are some note combinations that can be played on a guitar that can't be reached on a piano.
And what do you think a professional harpist thought when they first saw a keyboard instrument hundreds of years ago? Perhaps they trained for years, decades with a master and became sublime at the harp. Then they see a harpsichord or clavichord and from their point of view someone has just taken a harp a but a button rack over the strings so anyone can just push the keys and play the notes. They would take the same view as you that it removes all the subtlety from the playing. But look at the status of the harp today compared to the piano?
Non musicians who play musitude have a truly joyful and emotional experience and, as you said, the more they play the better they get and they start to develop technique. And in the end all that matters is that people feel joy when they play. We don't need to convince concert pianists and composers. We just need to see a smile on the face of our users and that's good enough for us.