Many ccTLDs are, or were, run via universities, so government funding was often indirect. Yes, often they operate(d) at a loss but not much of a loss, depending partly on volunteers and already existing infrastructure. That was often with the names being provided free of charge, so the cost wasn't that great, universities don't have $millions to run a registry. That was my point, it needn't be massively expensive to run a functional registry.|
It was a workable model for quite a long time and nothing major has changed over that period in terms of running a registry except that the demand for ccTLD names has often increased beyond the capacity of a university to manage it. This has less to do with an inability of the hardware and software to scale, and more with requiring additional personnel.
So fine, new rTLDs may have to start small and grow as necessary. If they had a variable pricing structure this would help. That is, as there would be some names most in demand and as those would likely be the first to go, then price them accordingly. Perhaps auction them off. Using my example from elsewhere I'd pay $100/yr. for fnord.books. But I'd probably pay much more than that for rare.books. Thus the registry gets a jumpstart in funding early on.
I wouldn't point to .tv as an example of how to do this though. They had investment funding, including from VeriSign (who has since bought them), so at one point they had over 85 employees and very fancy digs. That's the typical 20th century dotcom pie in the sky model which is now thoroughly discredited, so that is hardly a model to point to, even if it was successful. Seems more grounded in fundamental business practices to me to start small and scale as necessary.
As for IOD or new.net (or anyone, I don't know why you picked those two) being given a registry and failing, that is why ICANN has, or should have, contingency plans in place, including escrowed data. ICANN can then offer the registry for bids as they are now doing with .org. The only doomsday scenario is if there are no takers, and if the market has gotten that bad, that will be the least of our worries. -g