You could make the same argument about putting slashes in filenames (or, I think, even colons on old versions of Mac OS), and yet we accept that limitation gene

You could make the same argument about putting slashes in filenames (or, I think, even colons on old versions of Mac OS), and yet we accept that limitation generally without question. FWIW, I generally make sure most of my shell scripts support spaces in filenames--and am in fact more pedantic about it than almost anyone I have ever met--but for a developer tool as part of a build system or whatnot? No: developers should know better and I have no sympathy if they insist on spaces in filenames as it just isn't worth the productivity loss to everyone across the entire stack.