Erel,
Just giving an idea and reason for it:
I was searching on the forum for the same stuff, command line compiling.
The fact is that when the language gets more complex the projects also gets more complex.
With the compile to library a problem a great solution for packaging and code organization came to reality.
However a new problem that soon will be each time more evident: library dependencies.
For what I can see right now the b4a project file is somewhat simple. That is fine, the IDE is growing.
A command line option could be a simple way to solve more complex project needs without getting the IDE more complex. This is a way to create Make files, for example, get souce code from SVN, compile the libraries in the right order for dependency, generate apk builds (including versioning of the apk).
This way you even open the door to someone (i would do that for sure) a tool to handle this make file and control all dependencies and versions.
So we develop and test on the IDE and build ande deploy using the make files. You could also add on the IDE menu (on project) a way to add command line options for build and other for deploy (that increments the version).
My 2 cents.
Regards,
Eduardo Elias