The specific details of the LAF are not as important as the overall idea of a framework. A framework is used to solve a narrow range of problems. If the problem you have to solve fits the framework, it can be a great assistance. If the problem you need to solve is outside the bounds of the framework, then it may be very difficult to adapt. For example, the LAF works fine for small applications with a single window -- if you need two or more windows then it is very difficult to use.
And finally, the idea that inheritance can be used as a primary technique for adding specialized behavior to a framework.
Frameworks are not limited to graphical user interface systems. In the notes at the beginning of this chapter I discuss a framework for a simulation system. There have been many other types of frameworks described in the literature.