I never understood why they don’t support the subsonic protocol.

I mean… you might as well ask why the DLNA plugin has been broken for years. Or why they don’t add a custom HTTP header to the client app so people can lock access in their reverse proxy.

As usual it’s a mix of not enough developer manpower and “I don’t use that so it’s not a priority” i.e. the whimsies of FOSS.