And yet it is done as proven by new software development efforts for antiquated platforms like the NES, SNES, GBA, N64 or PS2. New cartridges are being made today. The original vendor has no responsibility to make alternative software easy.
But I believe they should have a responsibility to not make it impossible or intentionally harder than necessary.
There is the small fact that, once those platforms became antiquated, the population that constitutes "average users" also changed significantly, skewing vastly more toward the more technical end of the spectrum. They are therefore not valid examples to talk about here, IMO.