Because the casual observer doesn't know any better and is happy just to have their "knowledge" of these matters shaped for them.
An interesting thing I noticed - I was working during Origin III and had the game on my phone in front of me, half-watching and only really paying attention when the commentators went off or the crowd noise increased. My recollection of that game is exactly what the commentators said during it. Reading the live game thread afterwards (though admittedly biased towards Qld) was like an alternate reality. Did those "things" really happen? Surely this is just hyperbole by impassionate one-eyed fans. But when I finally got a chance to watch at least parts of the replay, the events occurred exactly as it was described in the thread, often very different to what the commentators were saying. And then when you see the moronic general FB/TW comments, they are almost always in line with the commentators.
It says to me that the majority of fans/viewers are just inertly watching the games, either observing as general entertainment (not a professional sporting contest), or half-watching it while they down a few beers and fiddle on their betting apps. The media knows this, and for every die-hard fan that lives and dies by their team's achievements, there are 20 out there more than happy to be spun a story that is entertaining but only very loosely based on the reality of the events.
