Possession is precious in Rugby League. In soccer and AFL and Union there is a (perceived) contest for the ball almost constantly. In League it is only mistakes, kicks, or collisions which turn the ball over. So if you know your opponent is going to complete 32/36 sets, you can't be giving them the ball carelessly. What if the other team won't give it back?
And this attitude is amplified throughout the game. Coaches preach ball control, players do, and fans too. Plus the commentators. You watch a dour arm wrestle and Gus/Sterlo say it's real finals footy - a compliment. Clubs pass the ball around and get accused of playing too laterally and shirking the hard work in the middle.
Jarrod Mullen went for a "trick" play a couple of weeks ago. Just on halftime he chipped for his winger from his own 20m and put it out on the full. His coach, arguably the greatest ever, cooked him in the press conference. Jarrod won't be doing it again. Which is a shame, because it would have been cool if it came off, and led to a try for the opposition anyway. Exciting stuff. But unfortunately, a master coach like Wayne will kick your arse if you try it.
So I don't think coaching creativity into kids is the answer because they won't be allowed to chance their arm at the top level. Clubs won't take the initiative because they it's proven that conservative footy works - it wins comps. So if people want changes, it has to be via the rules.