In the early 1980's, the ZX81 was the poverty specification machine. Rich kids had their fancy BBC Micro Model B, Atari 800, C64 or other proper machine, in a heated study room, with dependable electricity and other niceties.
Working class kids had the ZX Spectrum, Vic 20 or, if their grandma got the memo wrong, something like a Dragon 32 or Oric 1, which counted them out of the games swapping world of the playground.
Poor kids had the ZX81 and really poor kids had the ZX81 that you had to make yourself, the kit-form version that was £20 cheaper. Or failing that, a hand-me-down ZX80 or a Microbrain thing with just a hex keypad and a few LEDs.
Hence, although it might seem a great idea to make a ZX81 nowadays, for the British poor kid, it comes with the stigma, the reminder that it was you that had the kit-form ZX81, with no heated study room, and no 16K of RAM.