The NRL is on a seemingly interminable move towards bigger and more athletic players. I don't think its where we're at now that's the problem , but potentially where it will end up.
NRL forwards are getting massive. The younger Burgii are almost 19 stone apiece, Kasiano is almost 21 stone. They've been a big success so all sides are looking to find simlar players. We're also seeing small agile wingers almost vanish from the game, replaced by big, quick lads who are strong in the air as much as running. Souths won the comp this year in large part because they replaced an undersized threequarter line with 4 big strong players.
I think that's why there's a concern - if you follow this path to its logical conclusion, we'll someday wonder why there's no such thing as a halfback, as they'll all be 15 stone plus second rowers who can move the ball on and aren't a complete liability in defence.