This seems to close off the ability to solve a great many problems at all, though. Even in mathematics isn't it the case that algorithms often have specific cor

This seems to close off the ability to solve a great many problems at all, though. Even in mathematics isn't it the case that algorithms often have specific corner cases they don't work for, but they are tremendously useful for the vast majority of scenarios? i.e. not all matrices are invertible. And sometimes you can easily identify whether your situation is A or B, and deploy the right algorithm accordingly. Maybe that counts as "working for everything" in the Plan 9 model? It feels hard to navigate this for more complex problems in general. Is it bad to build a PNG decoder that only supports 8 bits per channel? Does a compositor need to support 32 bits-per-channel CMYK backbuffers just because someone might want them? Some people consider rarely-used features to be "Basic functionality" while others consider them obscure corner cases.