The problem with smartphones is that they're closed platforms (at least ios and android are). You can open them up a bit with jailbreaks but still... neither ios nor android even have a central file browser. Smartphones are definitely multi-purpose devices but not all purpose in the same way as a "proper" computer. They're decent for standard "consumer-level" stuff like checking email, browsing the internet, casual gaming etc, but for more specialized activities they're extremely limited.
Ok, i will bite, this is an interesting topic.
Firstly just to correct a minor error on C.A. Sinclair's part the android platform is a lot more open than the ios platform, and even has a file manager and for the most part full filesystem access, apps are not restricted to just their directory and jailed, and you can install what you like without any kind of permission from google and without a jailbreak. At least, this has been my experience of android 2.3 on the samsung galaxy S2.
Secondly, yes, i do agree that a lot of aspects of older computers were better. When i say 'older computers', I used to own a BBC Master 128k. It was a beast in its time, but still within the realms of plausibility for one man to know it inside out within 2 years, right down the the timings of i/o ports and the hardware level.
I loved that system, i loved the simplicity of the system and that i wasnt even afraid to take a soldering iron to its motherboard. I remember soldering in a switch to switch a memory range between an EEPROM chip and RAM, depending on what i intended to do that day.
I also remember sending off 16k of machine code i had assembled myself to be burnt to EEPROM so i could plug it into that machine, giving it functionality similar to a PC's BIOS password.
Who these days would know how, or even dare to take a soldering iron to their motherboard and/or extend their BIOS with homebrew chips?
I learned more in those few initial years on an underpowered old BBC Micro than i did in following years on my first PC.
Just to make you wonder, i owned my BBC Micro when I was 15 and at that time, the Pentium 2 was just coming into production, and the average RAM in a PC was 32mb. My BBC Master 128k had 128k of RAM (obviously) and a 640k 5.25 inch disk drive, with feeble graphics, but i loved it non-the-less.
In fact, the only thing that made me move to a PC was the ever-onwards march of the internet and its intrusion into our daily lives, and the fact that college insisted on teaching us how to program a PC.
Simplicity is king and i lament its loss under many hundreds of layers of abstraction, even if this is required for the average person to use a computer.
In effect, we have traded simplicity for the programmer for simplicity for the end user.