They exclude food and energy because they are volatile and can be affected by many different things that don't give a clear picture if the underlying trend.

Housing is excluded because they way they calculate housing is moronic and is a terrible measure. Housing is calculated with what is called "Owners equivalent rent." Basically, they survey home owners and ask, I'd you were to rent out your house, what would you charge. People answering a survey unprepared will not give a good answer for that, so the number is a terrible one to consider.