I agree with you on "lazy writing" part and that reflects in every scene of the film. They could not conclude the Anil Kapoor's character and kept it open. At the end, I felt bad about the three friends who got brutal deaths, though their roll is minimal and actually the heroine never died and hero never cared for the child.
For some reason, Mohit Suri seems to revel in the idea of revenge and a protagonist whose life resonates with downward spiral. Also, he has great taste in music, and the hits he has delivered so far piggyback on the songs in those films, which cannot really boast of having great scripts.
Once again, in Malang, you have a protagonist whose life has taken a dark turn and who is lusting for revenge. Once again, you have great songs that you want to hum for a while. And once again, you don't have a great script.
Malang opens with Advait (Aditya Roy Kapur) beating the crap....