We have to start somewhere, and private industry isn't going to start it because, as you point out, there's not many reasons to do it at the moment. The ISS is allowing us to experiment with living in orbit for extended periods. We certainly have to master those relatively simple conditions before attempting to survive a manned trip to Mars or living on the Moon.
Also SpaceX wouldn't exist without the ISS. It's NASA contracts for resupplying the ISS that kept it alive in the early days. Which just goes to prove the model: Government invests in "useless" project that allows private industry the toe-hold of capital needed to kickstart a new technology.
To your Antarctic exploration analogy, I'd say the ISS is more equivalent to McMurdo station than the Amundsen expedition
Also SpaceX wouldn't exist without the ISS. It's NASA contracts for resupplying the ISS that kept it alive in the early days. Which just goes to prove the model: Government invests in "useless" project that allows private industry the toe-hold of capital needed to kickstart a new technology.
To your Antarctic exploration analogy, I'd say the ISS is more equivalent to McMurdo station than the Amundsen expedition