You make a good point, and I certainly don't want to see the necessity for bail-out funds etc when one node in the settlement network goes under. I like your alternative, and it's probably more realistic, but I'm afraid it would create a much smaller ecosystem, perhaps tending towards a duopoly or worse, like one "Visa" and one "Mastercard". I want a rich ecosystem of actors competing against each other on fees, security, features etc.