You could be more gracious about this and acknowledge the fundamental point I was making, which was that all policy decisions involve social engineering, it’s inescapable, and it applies as much to “right-leaning” as it does to “left-leaning” decisions about transport. And laissez-faire decisions are impossible in some areas.
On the specifics: the question isn’t whether people and cars should be kept separate, because at some point they are going to mix, because pedestrians exist in the world and need to get to places and will have to cross the path of traffic etc. So the question is who should you prioritise when you build streets? For example, should a car have to stop for a pedestrian or a pedestrian for a car? A decision has to be made and whichever you decide is social engineering. It’s unavoidable.
Also, it’s just rhetorical bollix to say that people will still buy SUVs and trucks if we did away with CAFE entirely. I was able to walk downstairs last November and I can still walk downstairs today, but not having a cast on any more means I get there a lot faster — ie the importance of CAFE isn’t that it was the *sole thing* causing people to buy SUVs and trucks — I literally listed out a bunch of other drivers in my post. It was, however, one important accelerant.
Also, you sound very much like someone who’s completely unfamiliar with relative pedestrian death rates in Europe (pedestrians commingle much more freely with cars, death rate relatively low) and the US (pedestrians much more separated from cars, death rate relatively much higher and going in the other direction). If you had been at all familiar with these, you surely wouldn’t have made the rookie error of suggesting that the safest way to manage streets is to keep pedestrians well away from cars, when that’s clearly not borne out by the evidence. If you’d ever been to Europe, from Oslo to Paris to London to Amsterdam to Madrid, you’d see this for yourself: the streets are clearly safer in both urban and suburban settings and yet pedestrians mix much more freely with traffic.