I agree, but for a different reason, at least on the current map (Ndsiles?)...
The really big bases are very hard to take on Crater, but on the current map it's nearly impossible: very long drive for spawn and you pretty much need a GV assault to take one. The central ex-Vbses (now airbases) are a good thing, but switching the large airbases on the margins of the central island to megabases is not. No one bothers trying to take them because it's a waste of manpower to try, so that directs combat away from those bases. Why even bother to have them then?