for a bunch, it's that their entire personality is wrapped up in burning carbon. they know it's bad. they're not completely stupid, they simply think their hobbies - vroom vroom bullshit like cars, bikes, trucks, dune buggies, rock-climbing jet skiing etc, they think it shouldn't count because some other asshole is producing even more carbon than they are.

the cult of vroom vroom is gonna watch cars race in circles until we don't have a breathable atmosphere, and they'll never admit they're the fucking problem too.