The backslash (\) in DOS filenames has often been cited as the " *stupidest thing BG ever did " since by using the character that most other systems used for the "Esc" (Escape) character, there was no simple way to insert an Esc char in a script. Since most printers and modems in the early DOS era required the Esc character in scripts to get them to work, I presume I am not alone in having compiled my own several pages (and several versions) of "100 or more ways to enter the Esc char" as a ready reference tucked in the rack where the fanfold paper for the printer came out.
* This particular "stupidest thing" certainly has been displaced by more recent ones, so please - no arguments about which is the current one.