Another reason may be that few network professionals really wants a GUI tool. They want something that's readable yet concise, supports just the right amount of macro processing, and is easy to deploy on a large scale. It's not strange that Cisco is still highly regarded despite the fact that they never made a GUI tool that people actually use.
Most home users just use a web based configuration tool, and there are many capable ones. No waiting necessary, but that's a very different problem space.