One of the things that make the story in the original work is that the hero and the villain's demeanor and behavior are reversed: Oh Dae-su is half-crazy, desperate and clearly suffering from a psychological trauma, while his nemesis (forgot the name) is cool, calm and collected. It's believable that the latter would come up with and carefully execute a scheme like that (and be patient enough to do so), while the former would be driven and obsessed enough to get caught in his trap.
In the remake, meanwhile, the characterizations are reversed back to be more conventional, which in turn makes very little sense. So now Brolin is a one-note, seemingly stable badass taking out anyone standing in his way, and Copley is a cartoonish over-the-top maniac who could never create and follow through on an incredibly complex, 15-years-lasting revenge plot in anything resembling the real world.