I actually didn't see the answer I was looking for in there: command line/file system environments used to be all caps and there WERE NO lowercase letters for a long time. I remember when MS-DOS (whatever version) first began using/allowed lowercase filenames and it was like stepping into the future
"Historically it wasn't possible to make lowercase `readme` files" doesn't explain why, after transitioning to systems which allowed separate case in file names, `README` files remained uppercase while most other text files now have lowercase names.
