Are you really Irish? I'm assuming you have never been over here (I'm from Liverpool, England). NRL and Super League are incomparable. There are many ways I could show the difference, but I will use one. Outside the towns (and Leeds and Hull) that the Rugby league players here play for, they could walk down any high street in the U.K. and virtually no-one would know who they are. Sam Tomkins spoke about this. It's a culture shock to the top players who move to the NRL and become recognised in Sydney for example. Go a few miles outside Rugby league towns like Widnes and you enter an area where the sport basically doesn't exist. The big cities in the north of England like Manchester, Liverpool and Sheffield? Forget it. And it's in the north of England where all the English Super League teams are located.
There is not one Rugby league player here who is a household name. The last time there was was probably Martin Offiah over two decades ago when Rugby league was on the BBC's Grandstand, but he'd largely be forgotten now. I'd guess if you asked the man on the street to name a Rugby player it would be Jonny Wilkinson due to his winning kick at the 2003 RUWC, a player who is retired. While Rugby Union has a profile at international level here with the Six Nations and Autumn internationals, it too wouldn't have a current player that the general public would have heard of.
In terms of team sports the Premier League gobbles up most of the sporting landscape. TV coverage is swamped with it. Sky Sports News lasts one hour, a good 40 minutes plus will be PL, lower league football, football internationals. Talksport radio station is wall to wall football. It's the only team sport that would have household names. Following them would be individual sports, tennis players, boxers, golfers, and lately, cyclists.
Sports viewers here generally don't follow more than one team sport. I was different in that Liverpool are my PL team and St Helens are my Super League team. Everyone in my class knew pretty much every Liverpool player, but I was the only one who knew Sean Long for example.
It's totally unfair to expect Super League to be anything close to NRL. £250 million over five years is actually a decent deal for the size of the league. Crowds average 8.5k which is between the 3rd and 4th tier of English football. Sponsors also tend to be northern. The sport actually does pretty well just to stay professional.