This is certainly not the response I was expecting to get. To my mind the piano is no more than a bunch of strings of varying thickness and widths, and a bunch of hammers to hit them. If we ignore the keyboard section, all pianos sound the same. To put it another way, a black Janko piano and a pink traditional piano sound exactly the same.
I find it odd that some of you take this so personally. I realise some of you are experienced piano players and I am not here to crap on anybody's keyboard, in fact, I thoroughly envy your skill. What I am trying to say is that, from a beginner's perspective, there are alternative keyboards that just happen to be undeniably easier to get up to speed with.
To give you an analogy, I am a native Spanish speaker and learnt English and Chinese later, both of which I speak comfortably now. However, it took me much longer to achieve fluency in Chinese than it did in English, because the Chinese writing system is a b*tch (anything under 3000 characters and you can't call yourself literate). Now that I am familiar with both languages, I have no issues switching between the two, but I'll be honest: getting good at Chinese was definitely a lot harder. Furthermore, I know people who have spent over 10 years in China and still cannot speak the language, all because the user interface (the writing system) places the state of mastery further from the user (the speaker).
The traditional piano keyboard presents a similar problem, and while it is easy and comfortable to play once mastered, like any skill, it's harder to master. The Janko keyboard was designed to make all major/minor/etc scales look the same, respectively, which makes transposition a trivial task, certainly not the case with a traditional piano. Thus, the Janko design automatically divides learning effort by 12 for beginners, allowing them to focus on technique rather than the arbitrary constraints and idiosyncrasies of an anti-ergonomic and counter-intuitive user interface, and providing a more pleasant learning experience. The third video in my original post explains other advantages. I don't see how anybody could disagree that easier is better.
On a Windows computer Ctrl-C is the standard shortcut for copy, and when an application uses a different shortcut it drives us nuts. Why? Because we like things to be consistent. Consistent is good. Consistent is easier on the brain. Any two major chords should look the the same on a piano keyboard. I can tell a major chord from a minor chord, but I can't tell two major chords apart if enough time is allowed in between. That's because, like most people, I don't have absolute pitch, therefore I shouldn't need to worry about how them potentially being different on the keyboard! Conversely, any piano player would be able to play just as well on a transposed keyboard.
The QWERTY keyboard, also mentioned in this thread, is no harder to learn than any other keyboard layout. I have actually looked into ergonomic keyboards, I even made one for a university project 8 years ago, but eventually returned to the ubiquitous QWERTY for practical reasons: virtually every keyboard in the world is a QWERTY keyboard. However, that's not to say it's well designed. Nobody needs to take a second look at a standard QWERTY keyboard to tell you that it is an unfortunate design, the main reason being that the keys are arranged at a slant. This makes typing very comfortable for the right hand, but not so for the left hand. Electronic keyboards, unlike mechanical typewriters, don't really need to be this way, yet they are because by the time the first electronic keyboard came out everybody was already familiar with that layout, and so it was too late. NEC made a number of ergonomic keyboard in the 80s but they never took off and manufacturers quickly realized that sticking to the old layout would make them more money, so that's what they did. In my opinion only the geometry of the keyboard matters: the actual distribution of the characters is immaterial e.g. QWERTY vs DVORAK, because it depends on what language you are typing. I can touch-type on a QWERTY keyboard at 70wpm comfortably, but I started getting pain in my left wrist from typing code. I figured out that typing symbols was the culprit, so I came up with a solution involving the use of footswitches whose purpose was to minimize the distance my hands needed to travel to type symbols. After just one week my cramps were completely gone. This proves that good ergonomics is always a bonus.
The reason why some very smart people have taken the trouble to design alternative keyboards is not that they had nothing better to do, or to prove everybody wrong; instead, their goal is to bring this wonderful instrument closer to everybody It should be noted that these people were also seasoned piano players themselves. Similarly, I intended for this to be a constructive and rational engineering/ergonomics discussion.