Ranbir Kapoor once said upon asking as why some of his movies flopped, why his role was unimportant, ‘I am that Bandra boy, who has lived a luxury life, traveled the world but does not know his own people except Bandra.’
Most of the Bollywood movie makers like Karan Johar, Yashraj films are plagued with this phenomena. They know the world but not their own people, the condition Indians live in, actual problems Indians face or what is it like to be Indian living outside South Mumbai. That is why most Bollywood films are senseless, baseless and mindless. However, directors like Anurag Kashyap who have experienced poverty and seen real India, come up with great movies like Gangs of Wasseypur.
South Indian movie makers on the other hand are so well versed with Indian people. They know what problems a majority of Indians are facing, their living conditions, their heavily burdened cultural values and they make 90% of movies based on poverty, corruption, police crime drama or rich girl poor boy stories. However, they make shitty, illogical and time wasting movies.
But just like bollywood, there in the south too are some great movies made in Tamil and Malayalam.
One can not entirely rate Bollywood as shitty or great, similarly to south Indian cinema because there are some great movies made like A Wednesday and worst movies like Thugs of Hindostan. If you are really into sensible movies, watch Marathi or Bengali movies instead.