This comment is unhelpful and ineffective, for if it were so easy, it would be done already. People have to live with the decisions that their grandparents' generation made because the inertia of it puts it firmly out of the reach of the individual.
You get that we're talking about individual "responsibility" versus collective mass impact, yeah?
There aren't enough sufficiently-walking-friendly places to live at affordable enough rates to support most individuals in the United States going "welp, guess I'm not gonna drive". Devolving to individuals erases responsibility at levels where the necessary power actually exists.