[pvg]

It's still largely arbitrary. I'm pushing back against the general notion that standard Unix-y command line tools are some shining example of consistency. Most of it is just us confusing familiarity for consistency.

[Wowfunhappy]

There are some edge cases, but those cases are well-known and simple to understand.

[pvg]

If you haven't run across it before, google up The Unix-Haters Handbook for an entertaining book-length rebuttal.