Assuming the ILC could agree on an IAL, wouldn it be an unwieldy compromise? Wouldn a functionable language require the coherent vision that only an inspired individual could provide?
No single person can possibly know enough to construct the IAL. The history of the movement has demonstrated this, though Schleyer, Zamenhof and others deserve every plaudit for their valiant attempts. Informal collaborations have fared no better: they have always split on controversial issues. A congress or committee such as the ILC solves these problems by vesting authority in its unanimous or majority opinion. Of course there is a danger in this too, so a properly constituted arrangement is necessary – one which incorporates systematic consultation with all interested parties into the decision-making process. There is no reason, in fact, why the official committee and their consultees should not collaborate for the benefit all concerned.