In SSMS 2016, Navigate To... is gone.
So the answer is that temporary presence of non-functioning Navigate To... feature in SSMS 2014 looks like forgotten artifact of adopting SSMS to Visual Studio platform. Perhaps we should seek nothing more serious behind it.
Comment: SSMS 2016 is much more polished, it fixes many weird technical and design errors seen in SSMS 2014, including non-standard keyboard shortcuts. After leaving good SSMS 2008 and 3-of-5-stars experience with SSMS 2014 I recommend installing SSMS 2016, which can get 4.5. They even can be installed together, if someone is hesitant to uninstall that 2014 thing on the first day.