Okay, okay, so I apologise that I don't know what I'm talking about, and at the very least should have said "some airlines". C'est la guerre I suppose. However, three of the four airlines I have worked for in recent times have required an ASR to be filed in the event of any G/A. It's not really a monumental task, and at the end of the day it's a pretty poor display of management, if performing a G/A requires a visit to the upper echelons to explain oneself, every time such an event occurs.
The law as it stands requires an MOR to be filed in the event of a G/A which produces a hazardous or potentially hazardous situation. Clearly, that sort of episode rarely takes place, but some airlines prefer to gather information on all G/As, whether ATC, airframe, pilot or weather related, in the form of ASRs. Quite why the possibility of having to file an ASR would make you avoid a G/A is, I'm afraid, something I don't quite understand. Still, I guess stupidity is another trait I must learn to deal with.