Geez blokes must get bored when they retire. Either that or they really are dumb merkins.
I think they are dumb merkins basically. Think about it. Because they are large and athletic, they get fast tracked into a fantasy world where for 10 ish years they can earn more than an average working man can earn in 40. A career bedecked with fast money, attention from women, fame. They are adolescents frozen in time with no reason to think about their future. They are surrounded by their mates who are in the exact same situation so there's no one to tell them they're a massive danger to themselves.
By the time it's all over they've been to hundreds of parties that have been supplied by scumbag hangers-on. They make "contacts" who want to tap that fat footy player bank account either in naked scams or as seed money for alleged ventures like this one allegedly appears to be.
These big kids with a heavy piggy bank have no reason to look at the long term. They don't have a reason to stay faithful to a good woman because another bimbo will always be there waiting with her legs open. They don't need to invest in a post-footy career because a bikie named Mouse has promised a massive score from Brazil; all they need is $200k and it's all sorted.
Big dumb footy player just goes DUUUUHHHH MOAR MONEY FOR ME OK.
All of the above is hypothetical and in no way reflects any real player living or dead.