They were and still are extremely powerful and productive machines.
[1] http://en.wikipedia.org/wiki/BBC_Micro_expansion_unit#ARM_Ev...
We really are building things with too deep abstraction hierarchies causing knowledge to be divided
Abstraction is necessary, true, but it's not clear to me what the abstraction-level we have now really gets us. In other words, say we had a BBC micro with a 2Ghz 6502 in it. What productive computing tasks that we do now could it not do? Or let's imagine an Atari ST with a 2Ghz 68000, to get us a little more memory. What could it not do, that we need to do now? I'm struggling to think of anything.
application -> xaml -> framework -> server -> container -> c# -> cil -> bytecode -> x86 instructions -> microcode.
Now forth on a 68000:
Forth screen -> 68k instructions
To be honest, for what I consider to be life and death stuff, a 10MHz 68000 is good enough (I have one in my TI92 calculator).
Such as what? 99% of websites are a) screens where you enter something into predefined fields, to be stored in a database and/or b) screens that format nicely for display things that you or other people have previously entered. They were doing that in the 1970s. Only the buzzwords change.
If you could start again, would you really end up with HTML5?