The fact is GOT is only on HBO most people do not have HBO. Therefore most people dont have access to GOT. Now yes if you are tech savy you can finds ways to watch it(i do) but most people do not know how to do that either. My comment were based off my age group(35) and my local friends around az. (20-40yrs) and i would say more than half do not watch GOT.
Dont get me wrong its a good show with a great following but its nothing compared to the legacy of star trek or star wars.
and when i said most that means more people do not watch GOT than do. simple stats since it is on a premium channel and most do not have access to it.
I mean what 9 mil watched the last episode and i believe that is world wide. There are now about 320mil people in just the USA. So even if that 9 mil stat was just USA only 2.8% of the population. so 97.2% did not watch it. So yeah most people do not watch the show.