So in short, league in both Aus and Pomland promoted itself as being pro but was functionally semi-pro for most of that time. Not a good business move.
I understand the fossilized class differences between codes in England, but from what I can tell that's shifting (and Manchester now rivals London for wealthiest people in the country -- from what I understand, economically, the north is doing better today than just about ever). I've also seen current players talking about how they never really had to deal with those differences when they were coming up -- I wish I could remember who it was, but one of those times was a joint interview with a league player from Salford and I think a player from Sale, but that was 3 or 4 years ago. There's plenty of fluidity between codes in England today, but it's almost all in one direction. You see some league players go to union and return, like Joel Tomkins, but I don't know of anyone today who starts in union and then cuts to league. (Tomkins had a pretty successful return to Wigan -- I'd be curious if he credits union for developing him in any way that served his league game.)
You hear about those class differences between codes in Australia, but my sense is they hold even less there, especially when league players are second to AFL players for public profile. So I think the criticism there stands -- for a code that does as well in Australia as it does, it's a bit rich for its millionaire former players to call themselves working class, and they missed a trick by waiting until union ate their world-wide lunch to concern themselves with growing the global game.
I'm in/from the USA, so I don't have much of a handle on how the class differences might work in the rest of the world. It's a growing game here, and maybe more prominent in east coast private schools, but it's also more of a public game on the west coast. The biggest barrier is availability, not economic bracket. (It's a perfect game for the Upper Midwest, and if it ever takes root there, don't be surprised if they start providing a lot of the national players.) I imagine it's a similar story in Canada, although they do a much better job at organizing the game at a national level than the USA.
I know for years union was a working class game in Wales, a game miners played -- that's even in folk songs. And then South Africa has its own historical issues, but it's hardly a one-class game there anymore, and they don't seem particularly interested in league. I doubt league could be introduced there via an appeal to the non-Afrikaner population.
I lived in Ireland for a few years (where I first got into rugby), and to this day I'm still not sure where the public stands on the game, at least in terms of class. It's probably the fourth game in Ireland, with Gaelic football, hurling and soccer ahead of them. But you'd still see the pubs and stands full during national games, and I don't recall any class-based retribution against any code (but I could have missed it). If the Irish are playing in a sport, the Irish will get behind them. At the same time, it's similar enough to Gaelic football that there's some cross-over in support (and players), and I have yet to see Irish supporters talking down any other Irish team because it wasn't their code of choice.
The only sort of problem I've seen in Ireland is some petulance by people who it seems were either bullied or felt otherwise threatened by rugby players in school and use that as an excuse to talk down the code. Ken Early from the Irish Times does that all the time on the Second Captains podcast -- knows nothing about the sport despite having to comment on it on occasion, and proudly foregrounds that. He went to the Ireland - South Africa game, and spent most of the time drinking beer with some conference-goers he went with and not watching the game, then complained about how it's too hard compared to soccer. He seems to actively work to get names and details wrong. But that could be just because Ken Early likes to be a prick, not because of any inherent class-based differences.
Rugby is also the one sport that binds the Ulster to the rest of the provinces on the international level -- in rugby terms, they're more unified than Queensland and NSW, and they fought a civil war.
