Really, it's the "cub first mentality" restricting rugby league? Hmm, doesn't happen in other sports eh? Tell that to Will Genia.
Personally there is no"one" factor, it is a combination of them. One thing though is people seem to think that if the NRL diverted its financial resources we would have this thriving international competition. If you think that then I think you are gravely mistaken as to how far an Australian dollar is going to go.
Further it is not the NRL's job to propagate rugby league in other countries.
Also you also ignore the impact of the players on this. Whenever there is an increase in revenue flowing into the game what do we hear? Players demanding an increase in the salary cap both here and in the ESL. Hence if you want revenue for expansion at international level, ways need to be looked at to generate that revenue at international level so it can be spent at that level. The IRL has what 1 full time staff member iirc.
That said competitiveness is one area that international rugby league games need, and let's face it, England are the ones who are way behind both the Kiwis and the Kangaroos in this area. I mean the simple fact that players who are reserve grade talents in the NRL go to the UK and become "star" players in the ESL tells a lot about England's standing I'm afraid.In the short term improving the standard of the ESL would be a start, especially if we ever want to see a genuine, regularly competitive England International rugby league team.