Special-purpose computers create a lot of clutter and confusion. Life before smart phones was pretty lame: you had a phone, a media player, a camera, a notepad, a GPS device.... Well, actually, you didn't have that stuff, especially when you needed it, because you left it at home rather than have a bunch of devices banging around in your pockets. Special-purpose computers are actually becoming less and less common as general-purpose devices like smart phones and tablets displace them from the mobile space.
What we need is not special-purpose computers but general-purpose computers specialized by form factor, running applications that are optimized for the form factor and its style of interaction. Sometimes you want to sit down and type a ten-page report or reply to dozens of emails. Sometimes you want to lounge on the sofa and watch YouTube videos. Sometimes you want to lounge on the sofa with someone and watch a movie on a big screen with a big sound system, and you want your hands free for other activities.
I know that sounds really dumb and non-visionary because it describes exactly what we have now, but what the heck. It's a beautiful world. I also know that by saying "It's a beautiful word" I'm destroying any usability credibility I might have, because actually all normal people are suffering terribly, but again I say, what the heck.
Your first paragraph falls under the "Pocket Exception" (proposed by Jesse Schell). If it's in your pocket, you want it to converge. If it's not in your pocket, its going to specialize. To steal his example: the swiss army knife is a great pocket device, but you'd never use a giant swiss army knife in your kitchen.
Have you seen the number of buttons on a modern rice cooker? Some rice cookers incorporate pseudo-pressure cooking, and some are even genuine pressure cookers. There are also combination convection/microwave ovens, and I love my combination immersion blender and food processor precisely because it serves two purposes in the same space as either one. It doesn't crush ice or blend as easily as the old stand-alone blender I had, but I compromised on features to save space. (It also has fewer parts and is easier to clean than the stand-alone blender or the dedicated food processor I used to have, so convergence didn't compromise usability.)
What we need is not special-purpose computers but general-purpose computers specialized by form factor, running applications that are optimized for the form factor and its style of interaction. Sometimes you want to sit down and type a ten-page report or reply to dozens of emails. Sometimes you want to lounge on the sofa and watch YouTube videos. Sometimes you want to lounge on the sofa with someone and watch a movie on a big screen with a big sound system, and you want your hands free for other activities.
I know that sounds really dumb and non-visionary because it describes exactly what we have now, but what the heck. It's a beautiful world. I also know that by saying "It's a beautiful word" I'm destroying any usability credibility I might have, because actually all normal people are suffering terribly, but again I say, what the heck.