This is not so iron clad if you do some basic reading or thinking. Research has shown that setting speed limits blow the 85th percentile increases crashes from vehicles having less uniformity of speed. Rather than work against something that is natural, they would be better off getting the people who actually listen to the speed limits to drive faster so that they stop endangering others.
Another way of looking at things is that higher speeds mean cars spend less time on the road. Fewer cars on the road implies that the distances between them are greater. Crashes only occur when distances between cars reach 0. Lower speeds as are being advocated by that article mean that the distances between cars will decrease, making things potentially more accident prone. All of those arguments about what happens in a collision do not matter when the cars never collide. For example, the German autobahn has far higher speeds than US roads and their collision rate is lower, which illustrates the benefits of having more space between cars from having them drive faster to get them off the road sooner.
Finally, it is unfortunate that attempts at safety are trying to make motorists drive slower, which will cause more car accidents, causing people to push even harder for more measures to prevent them, that are likely to be just as backward.