I would suggesting trying a "fiddly add-on keyboard" first before saying that :). Maybe the iPad Pro's keyboard is like that and I certainly thought that about the surface pro 4 until I decided to spend some time playing with it. Coming from only Macs for the past 6 years I gave in and bought a surface pro 4. Then I did the launch hackathon with it where I coded for 48 straight hours.
It's a FANTASTIC productivity device. Granted it may not be the best fit for everyone but I wouldn't cast absolute doubt on it without spending some time playing with it.
> What's the point of making an OS X machine in tablet form factor
I don't think anyone specifically said it had to be OS X but it would be nice to have a touch screen and have access to iOS apps at the same time at you have access to "real" apps to get work done. I had an iPad before giving it to one of my kids because I couldn't do very much on it productivity wise. As a programmer who doesn't work on games: 99% of my code could run, without issue, on an iPhone 4's processor. I wanted something portable that I could read with, play casual games on but also get real work done. iOS just can't do that for many professions.
It's a pretty good compromise, in my opinion, for someone looking for a full fledge computer that can also have the portability and usability of a tablet.