My gut feeling is, that this NPRM is an attempt to address the runway
incursion issue, and that ADS-B information would be used to augment
or replace radar information about the location of aircraft on the
airport surface.

I don't know what the plan is. The NTSB comment sounds like it may
agree with your point however I don't see ADS-B Out only solving that
problem. If you are correct, that is just another reason why it may
only help the airlines and the FAA.

Ron Lee