After wining AO 2008 Average Serb would think like this: "They put Novak every time in harder half cause whole western world is against us. They don't want to see Serb winning slams so rather see Fedal final, giving Novak harder opponent in particular surface."
Exception was RG 2009 when they realized that Novak came too close to Nadal (after MAdrid SF) and put Novak in Fed's half to tire him ahead of fresh Nadal.
Another more realistic possibility is that uncle Tony rigged draws to give Nadal easier way to title. This year they put Novak vs Murray cause they thought that Murray will rise with Lendl and stop Novak's dominance (because Fedal weren't able to). So, everithing is clear