Are they wrong?
There are couple of points to consider.
Young Australian fans know little about SL as there is no coverage of that League in Oz and they are saturated by the local game that they consider to be the pinnacle of the game (unlike the Premier League compared to Spain or Italy) different to your examples.
A better example would be an English Premier League fan knowing what is happening in Norway's League.
Lesser comps look up to the best at the Sport as the bench mark. The best do not really give a Rats whats below them.
Older NRL fans have never forgotten what happened in the SL Wars in Oz.
The decision by GB at that time will always stick in the neck of most Aussies.
Fine by me.
If Australians aren't interested in SL, then that's just great.
I honestly couldn't give a flying ###### if the inhabitants of some backwater 10,000 miles are not interested in SL.
The fact that some people feel the need to cream themselves over the NRL is, quite frankly, embarrassing.