The emphasis on flight's CO2 emissions confuses me and has me wondering if I am missing something. While fully loaded trains and buses are better it is still be

The emphasis on flight's CO2 emissions confuses me and has me wondering if I am missing something. While fully loaded trains and buses are better it is still better in per person miles than single occupant car road trips or even some loaded carpools. It strikes me as a "symbolically motivated" meme as opposed to a practical issue since air traffic is seen more as a luxury.