Junilu,
The nature of the universe prevents functional decomposition from ever working (there is no free lunch).
As the book explains, domain decomposition is still functional decomposition, but in disguise.
Therefore, by the nature of the universe, domain decomposition is precluded from ever working, as is evident with the monstrous balls of mud it often leave in its wake.
The only case where common domain decomposition can work is if the business domains map to areas of volatility, but that is just not the way most businesses are structured.
Interestingly enough, if you were to do non-business domain decomposition, that often is a good start.
For example, a domain decomposition of myself would include author, speaker, architect, father, husband, etc.
That will create a ball of mud, with all the internals and the external interactions between the endless domains, and I suspect you have seen that.
But a non-business domain decomposition of me would include the nervous system, the cardio-vascular system, the skeleton, the urinary tack, the digestive track, etc.
But these are also my areas of volatilities, and I preform the required business activities by integrating it all (see Chapter 4 on Composable Design).
Juval.