Sad news indeed. Like many here, I started my career in IT thanks to learning to program (badly) on a Spectrum and then later on at uni, (only slightly less badly) on a QL (via a BBC at school).
Several decades later, here I am writing backend systems* (now somewhat better quality) for multi-nationals. All thanks to that little black box with the colourful stripes and its younger, more powerful sibling with its structured BASIC and dual (dual! feel the power!) microdrives.
Seems like we've recently lost a lot of the greats of that time: Clive Sinclair, Rick Dickinson, Mike Singleton etc.
IMHO I'd think the C5 was the thing he most wanted to forget (IIRC at the time he said he dealt with the financial loss by just 'putting it out of his mind'). Whereas I think the ZX81 had a more positive impact on many of our lives. A significant milestone, it gave us something many had not had before - or could realize could be afforded that soon. Perhaps a bit odd, but one of the things I remember was that learning programming on the ZX81 taught me how to think more logically, how to analyse problems. A great help psychologically to me as a young adult at the time.
I'm glad Clive Sinclair was who he was, C5 and all. I think without that passion to change the world, even if some of his ideas were spectacular failures, I don't think we would have gotten some of the cool things that we love (not necessarily that everyone loves but that we lave-- the QL is a perfect example). There were always more layers to the things that he created than what you first saw. I just played around with my Sinclair Cambridge Programmable, just because I wanted to use one of his earliest devices, and man does that small white calculator have a ton of things you can do with it. It's cheaply made -- when I opened it up to look inside it basically came apart (didn't break, just came easily apart) but basically a Turing machine that is easily programmed. I just did a video on it which will come out tomorrow...felt that a calculator video was appropriate since that was my first electronic gadget (a TI-35 with Student book) and one of his first computing like devices.
"All your UK videogame companies today were built on the shoulders of giants who made games for the ZX Spectrum. You cannot exaggerate Sir Clive Sinclair’s influence on the world. And if we’d all stopped laughing long enough to buy a C5 he’d probably have saved the environment."