I disagree: the keyboard and mouse do not work really well. What they are is really easy to start using, and good enough.

The TouchStream takes at least a month or two to get used to. Most people spent that long getting started with a keyboard, and aren't willing to invest the time again learning a new device. Nor is there any pressing need except for power users.

For those power users, though, the TouchStream presents a potentially big[1] boost to productivity and comfort. At least, that's what I found.

[1] Where "big" is ~20%. That's only big if you're working 8 hours a day...

Have you ever actually used a Fingerworks TouchStream?

I have, for years, and you're simply wrong: typing on a TouchStream requires less force than typing on a mechanical keyboard.

It's "touch" for a reason. You don't press, you touch.

I work 8 hours a day on a Fingerworks TouchStream.

I can say with absolutely no hesitation that it's much, much nicer on my hands than the keyboard+mouse combo was. Actually that's why I switched in the first place.

This is easily solved, the touchpad can be a keyboard:

YouTube video

People get scared of using a touchpad as a keyboard, but it's much better for lots of reasons. Chords/gestures are much more powerful than keys, and you get integrated mousing.

They did, but not enough people bought it.

Youtube video

This keyboard is much, much better than a normal keyboard+mouse combo. But it takes more than a few minutes to learn, and it was always low volume, so they weren't a huge commercial success.

I can offer direct insight into your questions courtesy of years of experience using the Fingerworks TouchStream:

http://www.fingerworks.com/ST_product.html
http://www.youtube.com/watch?v=FDW5zyjhCbc

MultiTouch devices are very precise. In fact, moreso than a mouse for fine movements, because they take an average over the whole contact area so subpixel movements are possible.

You can have a keyboard. See the TouchStream. It works really well and is more efficient than a mouse+keyboard combo. Use of MultiTouch makes the keyboard itself vastly more efficient: gestures and chords are all available without leaving the keyboard.

I've played Doom 3 using the TouchStream. It's not as good as a keyboard+mouse combo but I'll bet it beats gamepad.