What would've happened if Jadoo had gone rogue in Koi Mil Gaya and thrived on human blood rather than dhoop? How would PK have turned out if he had attacked all the inhabitants of earth and taken them captive to his own gola? Too Hollywoodish, right? So why is it that only good aliens get an economy ticket to India while the bad-ass aliens get super-sonic, ultra-advanced space-warships to emerge straight over the Statue of Liberty?
Bad guys don't get to dance and romance with Bollywood beauties. Not even if they are from outer space. Be good, take the cake!
Bad aliens know Bollywood doesn't need them. For everything villainous, we have Prakash Raj.