I think the last point is where the difference lies. A pertinent question is, what is your assessment of the current system? If you're satisfied with it, then of course you would view the potential gain to be small. If, like many, you see the current system as severely dysfunctional, then the potential gain is significant.
I would say the current systems works well in the majority of cases, although it is far from perfect. As it only goes wrong in a minority of cases, the potential gain from any new system is quite small, so the increased risk from it also needs to be small to be worth it. This proposal doesn't fix every case, so it's gain is even smaller, and as such requires the risk to be even smaller, which it isn't.