I also think one of the major culprits of trading failure is trading too large. People get drawn into trading by the promises of making 3% to 5% to 10% per month--all promises that are far too unrealistic.
People go large because they have no other choice. They have not been tricked into it.
The reason hedge funds can succeed making the same bets as the retail is because all they have to do to make a living is making a couple of % a year. For the vast majority in retail, they could not make a living if they get 1000%.