It's the administration not the aviation, and you may not like the answer to that question
In any case, in the usual holy-war that ensues when GPS is mentioned, I think we may be missing the point here:
With an ILS you fly down the localiser beam - the closer you get to the kit, the narrower the cone, and the more sensitive *and ACCURATE* it will get. GPS is an area system, so the 3-4m accuracy will persist wherever you are.
7.6m positional error at the middle marker wouldn't seem a big deal - I would think 3-4 metres in the touchdown area could be quite significant. Seems this might be a case of choosing what you measure to make the results show what you want..