The complexity is one of the major problems of software development. Raise the level of abstraction helps reduce this problem.
We want the developer have more focus on technological decisions and business rules of project and not spend so much time solving problems created by the complexity of software development.

Take a classic example that illustrates the importance of abstraction:
The final code of a computer program (compiled) is very complex to be written by human beings. The compilation came along with the first programming languages such as Assembler. The programming languages are nothing more than abstractions to make life easier for developers, and for years and years languages appeared increasingly powerful and with a higher level of abstraction that facilitate the lives of developers.

But the key point of this topic is to have the maximum of abstraction without losing control and power than we are doing. This is one of the factors that separate languages successful, unsuccessful. The same concept can be used for a generate code tool. Our focus is to raise the level of abstraction without masking the code behind visual interfaces, ie: you have total control over all code generated by the tool and not be dependent on J2EE Spider.
This tool is based on templates, and you can customize it so you can reuse assets, components and standards used by his team. All this allows raise the level of abstraction without losing control and power.

Focus more on business is one of the concepts of Business-driven development.