The BR league will always be 3rd or 4th tier, because they will never be able to grow from having champions league football as competition. Copa Libertadores doesn't even come close. Right now, the players are staying for one reason and one reason only: money. There's more money in it than before, so they can tie down their talented players to long and lucrative contracts.
If Neymar, Ganso, etc had any ambition, they would be doing whatever it takes to play for a European club. If they want to be even close to Ronaldo/Rivaldo/Ronaldinho, they need to face insanely tough competition and step up. Playing around in their little sandbox in Brazil just shows how afraid they are of flopping abroad.