While I absolutely agree that you can't create a full game without coding, I think that a well-designed editor can help iterate logic, mechanics, gameplay, visuals, etc way faster that tweaking values in code. More generally, it is often very difficult to get that initial spark of inspiration when faced with only code. That said, I actually don't think that the traditional game engine editor UI is the best way to do this. Such editors help to set up a scene and perhaps expose some parameters of the components, but they don't help the user to make that leap from having a bunch of great assets to having an engaging game world.
All this is to say 1) having a great editor for Urho would ABSOLUTELY increase its value (not necessarily in a monetary sense - rather in the sense of the value that it gives the users), and 2) Given the incredible base on which to build (i.e. the Urho source code), it might be worth trying to envision an equally innovative editor.
I've actually tried to implement a bunch of the above in iogram (, , ), and I would love to see iogram become a more general tool for Urho users. Not sure how others feel about that, though. Also, I've posted a lot about iogram - I'm not trying to spam the thread ! I just think it is a relevant bit of work on game/3d editor UI.