They're talking about replacing cars with public transportation which is fucking ridiculous for the majority of the country due to low population density and large distances. There's no amount of zoning changes that are going to fix that. Also, creating walkable cities is a great goal, with zero chance of happening in the US. It would be asking home owners and businesses to throw away existing investments, or forcing them to. Guess how well either of those options is going to go over. Especially in an aging populace with nothing but investment income.