The problem that seems to be being missed here is that while fraud is one reason Visa has say over what they accept, the much much much bigger issue is ATF, Money laundering and Sanctions.

Cards like the Freedom card will never fly with either the Networks or the Issuing Banks as these kinds of payment instruments are immediately used to wash illicit funds.

Visa's stance with Steam is bollocks, and it is another example of the monopoly they hold over payment processing. They shouldn't have the ability to impact a legit merchants catalogue.

But the idea that we can have a Freedom card also doesn't checkout. The less known about what the money is spent on the higher the risk. And cost of complying with Suspicious Activity Reports regulations is really high (as the costs of you breach the requirements), so any attempts to create / run this kind of thing often don't stack up.