Why would an average Aussie know Blackpool Tower, Bruce Forsyth or Yorkshire Pudding?
If you reversed the situation English players would probably do worse.

I don't know many Aussies TV stars and I've been here for a long time. Mainly because Australian TV is so horribly bad and I avoid it like the plague.

I've been to Melbourne and Adelaide a few times and wouldn't recognise anything from either city. I wouldn't expect anyone to remember much of Brisbane either to be fair. Its hard to remember anything of note even when you live here. Sydney has the only world famous man-made landmarks in Australia.

So Adam Blair couldn't name any Wigan players who would pose a threat to the Broncos? Spot on, Adam.

Not sure if that is a trick to test people - but i'll take the bait.
Miller is a proud son of Victoria - born in the oddly named Melbourne suburb of Sunshine (which is the most dismal industrial suburb in Australia possibly). He was also a star Australian rules player.
He might have died in Queensland. Half of Victoria go to Queensland to die.

On how much young Australians know about England - not that much.
Our schools used to teach a very anglo centric version of history 30 or 40 years ago, and we used to have some English TV shows and movies, but these days we don't learn about dead kings and queens, and live royals only appear in women's magazines not read by anyone under 45.
If you go back to the 1950s or so, young Australian's travelling to England would say they were going "home", even though they had never been there, and Australian schools taught they same version of history as English schools, even to the point of calling Australian troops in WW I "British forces" - but now we learn history from an Australian perspective, and you are just a tiny island on the other side of the world.

"Wigan's danger men" ?
In the context of the current world series, it's not really a surprise that he didn't know of any.
Whether that is lack of respect or, having no fear, I'll leave it to you to decide.

Almost to a man the Aussie players were a class above any of the players in the English teams