I was not always in favor of touch screen devices. In fact, I viewed the early stages of this revolution in user interface with some disgust at it's first major inklings.
Part of it had to do with the DS requiring a stylus to be of any real use and, of the early touch games and apps, none using the new touch interfaces in ways that made sense with this new input device. In the phone space, it had to do with fingers covering the viewable area and a lack of muscle memory like we have with buttons (eg: you can't text and drive safely without a physical keyboard, because you have to look down).
However, in the 6+ years that have passed since touchscreens invaded our world, I have gotten so used to touching my viewing area that any devices screen that doesn't respond to my press, flick, or swipe throws off my balance, as if I was unwittingly thrown into a timewarp and ended up back in the early 2000s.
I could list a variety of reasons why the touchscreen is here to stay, and why that is indeed a good thing, but I have a story that proves that point much better than I could.
My mom's new camera is a perfect example of this vertigo felt by a lack of touch. Dad basically ruined mom's camera, and thus bought her a replacement. When asking which one she wanted, she decided to slash the cost by cutting out the touch screen model; so, even though almost the entire back of the camera is a screen, you have to do everything with the tiny buttons smushed against the right edge of the back.
I go home and see this new thing on the kitchen table and ask about it, picking it up and opening the shutter before mom can barely spit out a full sentence. As she explains its exodus (much like I just did for you), I snap a few pictures and then jump into the view mode to see the result of my wicked, mad photo skills.
While showing the pictures to her, I see some on screen buttons, presumably hiding features and whatnot behind them. I reach out and push them with my finger, and the screen does nothing. "Oh, it doesn't have a touch sceen," she replies, chuckling at my confusion. "That model cost too much, and I figured I didn't need it anyway." I told her she would be sorry for deciding that, and maybe a month later, after her first real outing with it, she confirmed that I was correct; she wishes it was a touch screen.
For the past four or five years, her phones have been almost all touch based. She has a Kindle Fire which I think she uses more than her Dell laptop. Her e-reader, another Kindle device, is a touch version. She is interested in Windows 8 ultrabooks and definitely wants one with touch screen on it. Each time she adopts a device that is more touch focused, she is happier with it. So, why in the year 2012, after having all these touching devices in her possession would she back-track?
My assumption is that, for her, this touch interface is a very recent, and very short part of her lifetime. For half-a-century, she got by just fine without these things and so of course she can cut a few corners, save a few bucks, and be comfortable with a new camera that controls like something built five years previous. But when all is said and done, she just can't do it because, like most paradigm shifts, once you are part of it, moving backwards is near impossible.
Once you had a TV, settling for sitting in-front of a radio would never be good enough. Once you had a personal computer, the typewriter was bound to collect dust. When you bought an mp3 player, your portable CD player was as good as junked. And when you move from d-pads, joysticks, and trackpads to an actual touchscreen form of input, going back is always going to be a pain in the ass.
There have been several other events since she got this camera that it should have been at... but it wasn't invited. Instead, she uses her smartphone to snap and share pictures, cutting out the process of moving files to the computer before sending them out. And, this way, she gets to keep her touch screen handy for everything from focusing, to jumping through menus, to browsing the gallery, to... well... you get the picture.
Does the fact that my mom ignores her low-tech camera prove that touchscreens are the messiah of user experience? No, but I think it does show that they've changed the game in quite a big way; and in my humble opinion, it has definitely been for the better.