It seems as if Microsoft came to the same conclusion as Surface Pro 3 is only offered with an optional Type Cover. I could always justify the Touch Cover's existence by saying it was better than typing on glass, but the reality remained that I almost always used a Type Cover with Surface Pro. The Touch Cover always offered the low profile behavior of a traditional tablet cover but it was never all that great as a keyboard.
In the first two generations this meant having two different options: a pressure based Touch Cover and a Type Cover with low profile keys that actually move. Along with the integrated kickstand, the Surface tablet was always designed around being used with a detachable keyboard cover.
