or on macOS, although I'm not sure it's still by default using case sensitive file system or not. I do remember the first time that bit me though, being a programmer using Linux collaborating with a developer using macOS. Must have been in ~2005 or something.
The one which bit me happened when I was running a java minimizer / obfuscator on a Windows platform and it assumed that A.class was not the same as a.class. It worked great on Linux and didn't warn that it had overwritten a file, resulting in a package which almost worked.
> Unlikely that they even consider checking whether they are stomping across existing names.
Or it's on purpose as existing terms already have good amount of search traffic for those terms, and Microsoft know Google/Bing will rank Microsoft's own pages higher than what's already out there.