Ripple is very difficult to understand and therefore is difficult to argument against it.
But what I understood it is centralized and not open source.
Another problem is that it needs gateways like exchanges by bitcoin and actually there only one gateway.
Without gateways to fiat you cannot transfer fiat money just Ripple.
So the problem which exists by bitcoin with exchanges by Ripple is even worse at the moment it is just hidden by the complexity of the system which is difficult to understand.
This is pretty much all true. But none of these things are fundamental about Ripple. It's just the difference between where we are and where we are going. You basically just summarized our priority list right now.