It’s not ignored, ultimately there are just other priorities at the moment. As a reminder, the votes on the roadmap do not dictate priority of a feature’s development. While I agree this is an awesome feature it’s also not one that will prevent game’s from being released and the overall result can sufficiently be faked to your artistic delight.
This feature was put on hold to get the forward renderer implemented, which is still being worked on. Hopefully after that research and development will pick back up, but as with anything no promises.