I agree, they need not be mutually exclusive, simply supplemental to each other. That said, it still occurs to me that there's a reason that it's not done on a greater scale, as in why we don't see very many omega farms. I figure it's because there is no serious food shortage in the industrialized world. If there were, increased prices would make such farms, in addition to the traditional models, very profitable. On the converse, building them and increasing supply would lower prices. While good for the consumer it makes farming in general less profitable.
Supply and demand. That's my theory as to why we don't see more omega farms.