Being able to feel your way around the keys is basically what allows most people to type without even taking a glimpse at the keyboard.
That's not the only purpose - being able to feel where a given key ends (and thus being sure you are pushing the right key), and having tactile feedback (so you know you actually hit the damn key) are critically important, and the reason why -for example- there's such a large and growing market for phone-compatible gamepads.
Honestly touch screen keyboards are - like hiding all of a TV or monitor's controls, inputs, and headphone jack on the back of the thing where they're nigh-impossible to get at - yet another example of minimalist design making things much harder to use.
Cue to why I still wonder why people even worship Steve Jobs that much :v, I mean sure, he was responsible for Apple's critical business manuevers (which in several points of Apple's history, were considered highly questionable) and most of the design choices (which, while looking pretty, pretty much defenestrated user friendlyness). He never actualy made an important contribution to the actual programming of the Mac OS and other software innovations attributed to Apple.
Steve Jobs, either due to maelevolence or idiocy, greatly impeded every genuine technical innovation Apple ever produced - he tried very, very hard to kill the Apple II (because he wanted to make machines for normal people, not filthy nerds, and the expandable, tinkerable Apple II line was a hacker's paradise), doomed the Apple III to failure (by flatly forbidding it to have proper cooling because nobody wants to hear fans or see ugly vents - the machine got so hot chips would pop out of their sockets, and the first troubleshooting step was to
pick it up and drop it to reseat them), doomed the Lisa (by pushing very hard for a shiny, idiot-proof interface that the hardware simply couldn't handle and insisting on using proprietary disk drives that were expensive, unreliable, and wouldn't work with standard disks), and would have killed the Mac if the design team hadn't mutinied (he refused to allow them space for a hard drive (like with the Apple II, he viewed this as a useless toy to pander to nerds), once again tried to prevent them from cooling it (for the same reasons as the Apple III), starved the system of RAM (most of the applications for increased RAM at the time were games (the era of business graphics and such had not yet arrived), which he scorned) and tried very hard to make Operating System much flashier than it needed to be - when the first-gen Mac had barely enough resources in the first place.) Not to mention cheating Wozniak out of most of his share of the profits (when Wozniak did nearly all the work, and was solely responsible for the capabilities that made the Apple II a juggernaut in the first place), verbally abusing his associates and subordinates, and presenting an "I'm better than you" attitude that rivaled the most arrogant people around today.
Job's later success with the iPod and iPhone weren't really technological advances either - portable .mp3 players were already on the market, and the smartphone was a natural and obvious extrapolation of what was already out there - it was little more than slapping a touchscreen on a Blackberry. The only "brilliance" was putting them in a shiny minimalist case, as technolgy had finally allowed Jobs to successfully aim products at the
idiots "normal people" that he considered his true market the entire time.
For all the praise Jobs gets as a technical Messiah, he's more fitting in the Satan role.