I see your point. Shorter would have been a great candidate for leading the free or semi-free camp, with his sense of form (which is lacking, for my ears, in most so-called free playing) - the tension comes from the ever ongoing conflict with musical boundaries, so you better not give them up completely.
As far as Corea is concerned, he was tinkling too much, for my taste - very occupied with his own stuff, and not as rhythmically communicative as e.g. Herbie.
But that music wasn't meant to be perfect ...