>I go the opposite way and rather question why slashes aren't allowed.

You mean aside from the obvious reason that a slash is the path seperator?

I'm thinking that a path should be a list of directory names (and possibly a file name at the end), not tied to any particular way of representing this list. In some contexts, such as in a shell, concatenating the directory names, with slashes between them, ("/home/bromskloss/hello.txt") might be the way to represent it. In that case, a slash in the name would have to be escaped. Other times, such as in code, an array might be cleaner (["home", "bromskloss", "hello.txt"]).

There are filesystems that let filenames consist of any Unicode characters. Tag-based filesystems do not need to rely on special cased path separators, as long as they provide a sufficient UI and API for file management and interaction.