Why is a 4 seater, only 2 of which you can use, different from a 2 seater, only 1 of which you can use. I must admit I am struggling with that a bit.
Maybe then, the concept of what consitutes an RAA arcraft and what constitutes GA needs to change. Maybe weight should not be considered at all, maybe some other perameter should be used, say, stall speed or indeed the number of seats fitted. Or maybe a combination of several things, maybe JABBA is right after all and CASA should review this end of the aviation spectrum.