Decoding Deepak's most glaring problem is apparent in its title: The suggestion that a person can be "decoded" betrays a fundamental misunderstanding of what it means to interrogate, interview, or otherwise investigate another's identity. Gotham Chopra, whose slick new doc intends to explore the inner life of his world-famous father, confuses attempts to understand a man with attempts to somehow "solve" him, and in the process misses what you might call "the big picture." He strains to dig deep, to get past the fame-generated public image to something real and true, but adopting the pose of a serious thinker doesn't automatically make your thinking serious. At least Deepak, whose Oprah-approved philosophical sensibility is anything but rigorous, has developed a conception of identity sophisticated enough to form a coherent worldview around, even if it does cause him to occasionally tweet things like "we are luminous star dust beings with self-awareness" and, seriously, "no matter can matter if matter is not matter."
Gotham's observations, by contrast, are much more grounded in a reality he can see and touch, and he's more concerned, as a thinker and as a filmmaker, with his own latent daddy issues than with questions of cosmic import. That predilection is certainly a source of the film's interest (particularly for those invested in Deepak as some kind of holy man or spiritual leader, who may find Decoding Deepak's "exposé" qualities illuminating or even outright revelatory), but it's also something of a self-imposed limitation, since it prevents Gotham from accounting for the scope of his father's philosophy. His subject, whether in truth a genius or fool (and it often seems the latter), at least strives to accommodate nothing short of the universe itself in his writing and thinking; that Gotham limits himself to an exploration of one man, however famous or interesting, can't help but register as shortsighted by comparison. It's as if he's too star-struck as both son and documentarian to see beyond what's right there on the surface.
Tellingly, Decoding Deepak shows no interest in engaging with, let alone actively criticizing, the actual work of Deepak Chopra. Its actual interests are considerably narrower: Gotham wonders aloud whether his father's habitual Blackberry use contradicts his outwardly spiritual character, or whether enjoying the frivolity of an affluent existence, from a preference for five-star hotels to a Starbucks addiction, recasts an ostensibly faultless saint as a shallow middle-class sinner. It isn't a scathing indictment, exactly; the film eventually justifies highlighting Deepak's personal blemishes as a humanizing gesture, and is explicit about doing so. But that unwillingness—or inability (it's made by his son, after all)—to thoroughly demystify the legend in which its most apparently interested makes it feel rather tepid as a work of investigative journalism or celebrity criticism. Gotham, perhaps anxious to appease his father while still wanting to impress him with a degree of candor, wants to have his analytical cake and eat it too: Decoding Deepak talks up its own intention of getting the "real story" behind the man beloved by millions so often and so ardently that the softness and paucity of what it delivers can't help but seem airy by comparison. In the end, it's merely lip service paid to an idea of a deeper work.