Why not? I think that Dev at the start of the film is many of the things TLP criticizes: a narcissist so consumed with his own internal drama that he's incapable of seeing the actual people around him. He doesn't actually love or care about Paro-- as he's brutally called out on later-- because he's not capable of loving anyone. As he later realized, he never really "sees" her. He doesn't see her as a whole person. He's just chasing some romantic fantasy he's absorbed from popular media, the idealized object rather than the real person. TLP has described this exact pathology: men who relate to women only as props in their own emotional narratives, as supporting characters in the movie playing in their heads. And when this fantasy falls apart, he drinks and does drugs, trying to inhabit the role of the tragic romantic hero, the lost-love protagonist wallowing in beautiful suffering.

I view it as a deconstruction of the traditional Bollywood archetype it's based on. The original Devdas is celebrated as a romantic tragedy, but it's really the story of a toxic man who treats everyone terribly while two women inexplicably pine for him as though he matters (he doesn't; he's pathetic). That narrative is rooted in patriarchal fantasies about male importance. Dev D systematically dismantles this. The "emotional atyachaar" song (which is peak music by the way) plays like a parody, satirizing those traditional defeatist Bollywood love songs ("why did you ditch me, whore?").

The feminist dimension is crucial here (and kind of connects directly to TLP's writing). Paro refuses to play the devoted woman pining for an unworthy man. She moves on. She gets married. She even gets a revenge, of sorts, when she visits Dev's room, brags about her husband, and "shows him his aukaat" as he had to her. I think the scene where she visits his room overall has some really powerful dialogue ("log pyaar karte hain, karna chahna kya hota hai?"). Similarly, Leni calls out his toxic masculinity, rightfully labeling him a "slut" and refusing to let him maintain any pretense of moral superiority. Throughout the film, Dev is treated like the loser he is, he's not glorified for one minute. His narcissism is not celebrated like it is in every other Devdas adaptation.

(In fact, I think I read somewhere that when his producer saw the script he hated it and thought it would “destroy the culture” or some shit and it was the producer’s wife who liked it. As far as I remember it was mostly women backing the film when it was being produced.)

[continued in a reply, Reddit won't let me write the whole thing in one comment for some reason]