Sholay is (though I admit I have not seen many Bollywood films) one of the more realistic Bollywood films I have seen or even one of the more realistic films in general that I have seen. One of the articles mentions how some movies have a universal quality that reaches out to almost any viewer. For Sholay, its universal aspect is based on the nature of the two protagonists Veeru and Jai. They embody the idea that no one person is completely good nor completely bad. They hail from thieving backgrounds --crimes of no great gravity-- but as they develop go on to prove that they have the capacity to change for the better and do good if they so choose.
In Khai's review, she discusses the appeal in the dual contradictory personalities of Veeru and Jai, and I would have to agree that there is some appeal in that. However, I do not think that their personalities are contradictory or ironic because I think it is just a good representation of human nature and how there is a little bit of good and a little bit of bad in all of us.
However, to juxtapose this idea of a mix, Gabbar enters the plot as a manifestation of pure evil. Khai does a pretty good film analysis of how he is shot with high angles. He is the typical villain from any movie, and he works as a good opposite for the duo Veeru and Jai. One good example of the difference between Gabbar and our protagonists is their honor. As Thakur is down, Veeru and Jai see an open route for escape. They decide with a flip of a coin to stay and help Thakur out. Gabbar also relies on chance; playing Russian Roulette to punish his disappointing henchmen. Though the henchmen luck out in this game, Gabbar does not honor their victory and takes their lives anyway.
The closing scene hits a bit close to home as Thakur's revenge is taken from him by the enforcers of the law. This movie seems to put the police in a bad light as they play a minimal role in defeating Gabbar, while heroic criminals do the dirty work. Then, at the end, they swoop in like vultures and take away the justice from a wronged man. In this sense, Sholay is a socio-political commentary.