As with most things, people will go to which thing is 'happening' at the present time. The Lions only 3 years ago were winning flags all the time. They were near unbeatable at the Gabba. So surprise surprise their games were packed. Now that they are rebuilding their crowds, surprise surprise, have dropped a bit.
The Broncos have been down for a few years. They won the premiership last year. Surprise surprise, Suncorp Stadium was full last night.
These days people in places like Sydney & Brisbane are just as likely to attend 4-5 different sports. They may well go to a Lions match. They may well go to a Broncos/Titans NRL, Reds Rugger or even Roar football match.
People who may well have been really 'into' the ions a couple of seasons ago just aren't any more. They may have swapped back to the Broncos again.
The Swans hope to get over 50000 to Homebush in a couple of weeks. There may well be a lot of people whose traditional code in rugby league, union or even football. Big deal, they have paid their money & have shown support for the Swans & AFL. That doesn't mean they still can't follow their NRL side as well.
JF (who went to a great Newtown Jets match today

)