I think I can agree with you in some regards. There is some nice potential that Black can have with a delayed ...c5 or ...e5. Plus, the fact that he has not yet committed his pawn structure to either plan is another card he has. But, in another way, he has not as much early control of the center. So in this case, we have to cater towards the rational of the Sicilian 2...g6, as that is the defense at hand.
But another plus is not only the fact that Black has held back the d-pawn, but he has also held back the e-pawn. If the opponent were to play eccentrically, there could be an opportunity to advance to e5 in one move favorably (for instance, if for some reason Black was able to launch a kingside pawn roller). I couldn't necessarily give an account of an opening as such, but to sum it up this way - Black has both pawns at home. This tempo ought to be good.
My friend regularly plays 1. e4, and he has a pretty good grip on handling both 2...d6 and 2...e6. I played 2...g6 once against him, without any theory, just for fun. The game went well beyond the opening, into late middlegame, if not endgame (I can't remember right now). But the point is, he was not booked on theory, and so that was to my advantage.