Re: Tell me again what problem this solves?
"Yeah, and that BBC Micro back in the 80's?" wasn't actually a BBC product, was it? Acorn designed the thing, but the BBC did apply conditions to the engineering. Daft ones, of course.
My dad acquired the original BBC spec for the BBC Micro, written to define what the BBC was looking for - naturally I read it (he's had a clear out since and threw the thing away before I snaffled it. Grr; but then again my loft is full of quite enough junk). The Beeb insisted on a linear PSU, fully socketed construction, and some other oddities none of which I clearly recall after all these years. A Z80 CPU was mandatory, one gathers to favour Uncle Clive (Sinclair, for those of tender years).
What we got was a 6502 powered beastie. Acorn did deliver the specified linear CPU and fully socketed construction for the early machines, but they were soon superseded because soldered-to-the-board chips and a switched mode PSU were better from an engineering point of view.
Yes yes the ROMs remained socketed along with RAM and a few other bits. Point is, the original spec was crap and it was provided by BBC engineers who just didn't understand how to do the job properly. Which is a bit odd, because back then, BBC engineers were exceptionally good at what they did.