Obsession with white women?
Many naked white females sexually objectified/ lusted after/ degraded - check out the 'party scene'. Old Kumar doesn't have much time for Indian women does he (nor korean/ black women etc), and neither do the film's producers. Are Indian/ Korean/ black women not sexy?
Add to that the glamourisation of drugs and anti-white racist stereotypes (stupid, dumb, hypocritical untrustworthy rednecks the lot of them) and you have a nice bit of Hollywood Liberal subversion. There are a few funny bits though. The bait to reel you in....