This movie may not appeal to a rational brain that looks at the world through the understanding about evolution and the big bang theory. And it must not also appeal to them. If it did, it would lose its purpose. A country where almost a billion people are ridiculously obsessed with religion can not be awaken simply through scientific data. Thus movies like PK or OMG through its narrative dipped in morality manage to awaken the masses.
At the height of religion, lies mediocrity. So you need to be mediocre to reason with it. There are plenty of men with vast knowledge on the scientific understanding of religion and think themselves fit enough to debunk it. Likewise many with thorough study of comparative religions who think they're fit to defend their Gods. If they sit to argue, the debate is endless.
But PK's motive is not to debunk religion or question God's existence. He tries to explain through his buffoonery that your faith is a personal affair and the people who you think can connect you better to your God are simply doing business. That religion must not spill on the public and it should cease to be an industry.
PK has a purpose and that is to invoke reasoning in the minds of those millions who aren't fortunate to have liberal education. Movies like PK should continue to hit the mainstream cinema. In doing so, a nation where the religion that its people follow defines their role in the society will rethink about how much wrong it does to the people.
However, the movie ofcourse purely on cinematic standards doesn't meet Rajkumar Hirani's previous hits. The subject itself is lame and exploited in OMG. There is no newer ambition in the plot. It's still hovering on the boring one God several ways concept. After all its conceptual flaws, it's still worth watching for its screenplay and dialogue. Try it!