Imo you can fuck your body or mind up in many jobs that pay a lot less than being an nrl player. Its part of earning a living. It's not like u dont know going in u can get concussions or fuck your body up playing. A bog average player earns more than most of us. You could say they have danger money in their pay.
It's also why I think it's bad form when ex players sue after they retire for fucking themselves up a bit playing. Well anyone post 2000 anyway, when players really started getting paid.