Current political landscapes have created an expectation that new accounts not require financial investment. Various factors create this expectation, but they're not in Steemit's control. It simply isn't realistic to expect new accounts to be widely adopted in the current environment if doing so requires an investment in money, rather than merely time.
I'd love to see this tested. We can all argue all day long whether or not new users are willing to pay for an account, but it's probably just waste of time. Easiest solution would be to try it for a while and see what happens. My guess is that it's just a marketing problem: if we explain clearly why an account is valuable, potential users will understand it and pay without complaining.
God I love science! As you point out, it is something easily testable.
Let's test it. Well, let's hope 'they' test it =p