Maybe you should try to contact http://wiki.openstreetmap.org/wiki/User:Jgpacker as he is the author of the proposal http://wiki.openstreetmap.org/wiki/Key:aerodrome which tries to fix this problem.
According to the wiki documentation http://wiki.openstreetmap.org/wiki/Tag:aeroway=aerodrome?uselang=en-US
aeroway=aerodrome should not be used in relations.
Beside this, i think that in the example you give, the inner members of the relation, are part of the airport, so no need for the multipolygon.
I’ll agree that the complete area has to be tagged as aeroway (including the buildings ?) that are currently cut out. See the “Out to Map” on the page that is linked by muralito
Sometimes you have inner areas which do not belong to the airport so it makes no sense to forbid the usage of relations for mapping airports.
aerodrome:type=* is already in use 130 times.
another key is aerodrome=* which is used 577 times.
I don’t see any complexity in the attached example. A simple polygon should be enought in this case.