Ok, if someone already said this and I didn't read it, sorry, it's a huge thread. But my friend and I debated this for about 2 hours a couple of weeks ago. He originally thought it wasn't cheating, I originally thought it was.
Basically, his point was that it's an innovation to make drumming easier and open up your playing style; he related it to Yamaha's Nouveau lug and the like. To the Nouveau lug I said that the pedal affects the way you play directly, whereas the Nouveau lug affects the way you set it up and only saves time, and while the pedal "saves time" (you could do the same number of strokes on a normal single pedal, it would just take longer), timing is important in drumming, but nobody cares if it takes you more time to set up your drums.
To his main argument, my point was that the pedal is innovation on the manufacturer's part, not the drummer's part, and since it's not a standard (eg you can't do what you can do on it on other pedals), that it's cheating. He countered this by saying that traditional double bass setups (2 bass drums/double pedal) are cheating, because the end result is the same: double bass effects. I said that traditional double bass is not cheating because it's using something that's already available to you (bass drums and single pedals) and just getting more of it (or in the case of a double pedal, emulating this effect). He said that double bass does the same thing as the duallist (double bass effects on a single drum), which it does not because it is not only emulating the effect but the actual playing style, and that you are still using your left leg; that you play double bass pedal/drums fundamentally the same: with both feet. Another point of his was that the duallist is a great innovation because it uses the upstroke. I told him that this the foundation of its cheating, because you can not utilize the upstroke like that on any other pedal, and that you really are not learning a new technique, just timing your upstroke. To illustrate my point, I said that if someone could develop a technique that would utilize the upstroke, then I would completely support it because it is innovation on the part of the drummer, not the manufacturer. As a reference, I pointed out that the heel toe, slide, and Jojo Mayer's techniques all emulate double bass effects on a single pedal, and that these are all innovations in technique.
This is basically how the argument went, and I was eventually able to convince him that the duallist is, in fact, a cheater pedal because it uses something that you could not use on any other pedal, and although it is a technical innovation, it is not a standard and will not become a standard, and since it is an innovation on the part of the manufacturer and not an innovation on the part of the drummer (such as heel toe, slide, and Jojo Mayer's techniques), it is not really innovative to playing drums (plus the concept has been around for at least 70 years anyway).