The PNWL is empty by default meaning all dependencies are scanned to build the DMO.

If the Project contains external dependencies (Project Settings->Dependencies) and the PNWL setting for the dependencies is "None" then no entries are added to the PNWL and the User's expectation is that they will be excluded from DMO scanning.

However since the PNWL is empty by default and no entries are added (as would be the case for dependencies with their PNWL setting as "All") DMO scanning processes all classes in all dependencies.

Adding the Project's default package to the PNWL by default would ensure dependencies with their PNWL setting as "None" are excluded from the DMO scanning.

See the "Is there any way to disable or manage project content indexing in DM 7.1" thread (on BSIG) for discussion with rhn-support-mputz