The desktop build still uses zips for NW.js exports, because extracting the files on a Windows machine breaks Mac and Linux exports, because Windows doesn't understand the special file permissions needed for executable apps on those systems. The zip file is configured to set the right permissions so it works if you extract it on the target system. See the tutorial Exporting desktop apps with NW.js.
That doesn't apply to any of the other exporters, which let you export to a folder in a desktop build.
Thank you for the explanation! I looked at the tutorial and tried to understand the best I could, so unfortunately there's no way around this? I only export for windows anyways (choose to export only the "win32" option), so I think it'd be nice if the option to export as a non-zip file could still be there somehow.
Plus, C2 exports all 5 builds as non-zip files, does that mean the mac/linux builds exported in C2 were broken all along? Or does it mean things changed since then?