Peopleperson is trying to dodge around saying they don't want to live near people who are lower income. Often this is a way of saying, "I don't want people with different ethnic, racial, or cultural backgrounds near me."
It's more the density that people object to, not more people, or more housing. It's when there's an area in the denominator. More density means more cars, more air pollution, more traffic, more noise. More accidents, more time searching for parking and standing in lines. It may not add up to ruin, but it's objectively worse.
That's typically how it's done, yeah. Intentional communities will often market themselves specifically as walkable or transit adjacent.
But there's no reason not to take the things that work well in them and bring them elsewhere. Traffic separated bike lanes and Dutch style intersections are common sense improvements that we can build that improve access without requiring a car.