Do you remember the model number for that 2.2kW stand mixer...
They're essentially the respective kitchen power tool brand equivalents of Ryobi and Festool. The KitchenAid looks better, is designed for simplicity and approachability, covers the typical uses of a home kitchen, and sacrifices high-end power for flexibility as a multi-tool.
The Kenwood is larger, heavier, and more difficult to clean and maintain. Its size gives it a larger capacity that most households won't use. It costs 2-4x more than the KitchenAid and AFAICT comes in only the stainless steel finish. Most of the power available to the Kenwood is useless to home cooking and baking.
Also the machine you mentioned is not sold in the US anymore. Afaik the only machine is the 800W Chef Titanium (which is what I have).
That's bizarre, because it was on sale in the US last year when I was picking between it, a KitchenAid, and a Breville.
Coming only stainless being a drawback and the KitchenAid looking better are completely subjective.
I can totally buy it being heavier, but why would it be less approachable? It's a wheel versus a selector knob.
I wonder how the 1.7kW would handle mixing pasta dough.
Being heavier and taking up more counter space _is_ what makes it harder to use, less affordable, and less approachable. The Kenwood would not fit on the counter where I keep my KitchenAid without removing utensils I use while cooking or sacrificing what little prep space I have. If I wanted to store it in the cabinet under the counter when not in use, the extra 4-5 pounds vs. my KitchenAid would make it literally, physically harder to use.
And yes, the appearance is subjective. KitchenAid trades on that; they have more colors and finishes than features. That's important to people who don't care if the mixer can't knead a dense dough or mix a triple-batch of a recipe in one go.
But even more curious, 1200W should work in the US. At 120V and 20 Amps, this gives 2400W max and I think continuous load is allowed at 80% of that, which would be 1920W. But even the Kenwoods in the US only have sub 1000W last time I checked.