Bad luck indeed, although looking at the details of e.g. the Acorn Electron which had that production bottleneck doesn't suggest they had significantly stronger technology at the time, pretty much all 6502 based stuff like their competition except for e.g. the also local Sinclair Research with its Z80 based systems. In the US market there was also the Z80 based and monstrously successful Tandy TRS-80, per Wikipedia significantly outselling the Apple II for a long period.
Tandy also had a huge retail network to sell its wares, it's Radio Shack stores were the place to buy random basic electronic stuff all over the USA. Per Wikipedia, in 1982 4,300 company stores and 2,000 independent franchises in towns not big enough for a company store. One reason I mention this is to ask, how big was it in the U.K. post-WWII until Thatcher? It became a very big thing the US in the 1950s, combining local capital and market focus with centralized and bulk product planning, technology, marketing, and often purchasing.
Hmmmm, Tandy also did a Motorola 6809 based "Color Computer" of some note, but its expensive/superior CPU prompted them to forgo things that made competing 6502 systems more popular, like built in sound and graphics for e.g. games. There was also a very American cottage industry style market in Z80 CP/M systems built around the S-100 bus.