If you look at how much they spend per day (poster quoted $700,000 daily but said unverified), how would it make any sense to provide the service for free? I won’t argue for/against releasing the model to the public, since honestly that argument can go both ways and I don’t think it would make much of a difference anyway except benefit their competitors (other massive companies).
However, let’s assume they did release it publicly, what use would that be for the smaller business/individual? Running these models takes some heavy and very expensive hardware. It’s not like buying a rack and building a computer, these models are huge. Realistically, they can’t provide that as a free service, they’d fail as a company almost immediately. Most businesses can’t afford to run these models themselves, the upfront and maintenance costs would obliterate them. Providing it as a service like they have been means they recoup some of the cost of running the models, while users can actually afford to use these models without needing to maintain the hardware themselves.