The touch cover was... interesting. I like trying new input devices so I tried hard to give it a fair chance. It's not as bad as its worst detractors say but it definitely had problems.
Clearly if you absolutely require tactile feedback, it was completely wrong for you. It feels nothing like a moving-parts keyboard. But that's the wrong point of comparison.
Instead, compare it with a tablet's onscreen keyboard. On-screen keyboards have zero tactile feedback too. The touch cover had extremely low weight and thickness, comparable to any flip cover (the iPad smart cover for example), but keyboard still allowed you to type without giving up half your screen space for an onscreen keyboard. Also, unlike an onscreen keyboard, you can type pretty naturally while the Surface is standing at a mostly-upright angle. (Try typing on an upright screen. Your wrists won't be happy.) And you don't get the screen smudgy with your fingerprints.
There was pretty nice audible feedback. When you typed, the Surface would make an audible click with each keystroke. The click was very low latency, feeling almost instantaneous, and as a confident touch typist I found that it gave me a pretty good sense of exactly when a keystroke had registered. It almost felt like when you pantomime typing on your desk (am I the only one who does this?) except I was magically actually typing.
However, there were two fatal flaws, at least with the first generation touch cover.
First, it was unable to detect keystrokes accurately if you input them too fast. When I got over 40-ish wpm, the keyboard started dropping keystrokes. Absolutely unacceptable. This may have been fixed in the touch cover 2, which has improved sensors, but by then I was too frustrated with the technology to take a chance on another pricey touch cover.
Second, it just felt unfamiliar to most people. My honest feeling is that if Microsoft had worked out the high-speed input problem, and people had been willing to give the keyboard a chance, they would have gotten used to it. People took a while to get used to on-screen keyboards on phones and tablets, but now most people feel comfortable with them and have decent input speeds (albeit still inferior to the speeds achievable with full-sized moving-parts keyboards). I honestly think that a touch typist could eventually get 100+wpm on a touch cover-style keyboard without looking, except to center your hands once in a while, if the device consistently registered keystrokes that quickly. But the Surface is such a weird product family to begin with, it hasn't taken the world by storm like the iPad did (mostly for reasons that don't have much to do with the hardware), and the touch cover just made it feel even more alien. So the market rejected it.
It's too bad. If the touch cover worked as advertised, I might well have kept it as the primary cover. When I pack my Surface Pro 2 it's one of many devices in my travel bag and any weight/thickness reduction is welcome. And of course when I want to use a proper keyboard I've got various mech boards which I can plug in.
