Sure implementation details matter. There's lots of good, traditionally built, well crafted small towns (with sidewalks!) outside of major cities that are "suburbs." Typically when an urbanist is disparaging the suburb they're talking about the common strip mall, cul-de-sac suburb type that isn't this. There's studies that show that these poorly built suburbs discourage walking and negatively affect health. Pick up the book Happy City if you're interested. It discusses how the differences in design of cities has implications on people's lives