Okay, I'll bite. I've had my K-S1 for almost two months. It's a good little camera.
On two points, they are dead wrong - that the K-S1 doesn't have typical Pentax strengths of IQ and dynamic range. It's as good as any of the other plastic bodies. So it's not a K-3 - it's not supposed to be.
As to the lack of "rugged build", yeah it's not a magnesium alloy body or WR - I guess this makes the K-x a terrible camera, too, and it's still pretty popular. Or the K-500. Again, the build quality of the K-S1 is as good as any of their plastic bodies. WR was simply sacrificed for size - the project engineer said it was a "truly painful decision". (Don't tell me they could have done it "if they wanted to". Unless you're a Pentax engineer and were there, you don't know that.)
I'll agree the ergonomics aren't great, but I've used film cameras that were as bad or worse. Sometimes you have to adapt to the tool, and sometimes the act of doing so is good for you. I actually would have been happier if the right side were flat like a K-01, plus it could have kept the big battery. But again, small size was the goal. The designers made compromises - some good, some bad, some I still don't know what I think. But that's very Pentax. In exchange for small size, the DA Ltd lenses sacrifice speed, WR, and some handling - those narrow focus rings can be annoying, especially with gloves on. But in the right situations, they're great.
Value: well, the K-S1 is now about the same price as the K-x at launch. The K-x had a bigger grip, but no AF focus points, and the K-S1 is superior in focusing speed, LiveView, IQ, video, FluCard support... Sure, you can get a K-30, K-50, or K-500 for less - so what? Two of those are discontinued, and the K-50 is at the end of its run. Older models are always cheaper. You can get a K100D or *istDS for a hundred bucks now. I doubt a K-50 successor will launch anywhere below $600. Some of us (not many, but some) are willing to pay a little more for a smaller body. If I'd wanted a K-50 or a K-3, I would have bought that. If I'd wanted to go mirrorless, I would have done that. I had been hoping for some time for something like a K-x successor, and Pentax made one, so I bought it, and I like it.
Edit: (Okay, I admit I'm in the "and another thing" phase of ranting
) Regarding "No reason to exist": I've read that Japanese women are severely under-represented in the camera market. It's obvious that the color options are directed at them - probably the petite grip as well. Maybe MILCs will dominate this segment, but Pentax has a selection of excellent small glass to go on a small body with excellent IQ. It doesn't seem that daft to me.