To add to your argument: I've never encountered a discussion, much less a proposal to throttle all cars at 10 km/h. That would save around 4000 lives here in Germany alone and spare many more severely injured, scarred for their life.
It's not about saving lifes, it's about getting re-elected.
Would it, though? Sure, 4000 _might_ be saved from car crashes. But how many would die by not making it in time to a hospital? From the likely collapse of transportation, and distribution of goods? From the extra pollution of going that slow? From the general economic impacts of such a measure?
It's not about saving lifes, it's about getting re-elected.