Why is it a nightmare? I use WebDAV almost every day. All my online servers support it, and it makes it super easy for me to map them as a file system driver in Windows, allowing me to edit files directly on the server.
Using WebDAV is generally fine, if you have the tools. The weirdness (the hell?) is when you're required to write those tools, or libraries yourself; most especially when the tools you'll write need to work with different flavors of servers. Each's adherence to the protocol is a little "loose" at times. Odd responses. Odd errors. The whole gamut. When it works, it works fine; when it doesn't it really is a bit of a nightmare.