Do India’s 1.3 billion people need English? Not according to Vice President Venkaiah Naidu. At an event last week in New Delhi to mark “Hindi day,” Mr. Naidu called English “a disease left behind by the British.” He praised Hindi as a symbol of India’s “sociopolitical and linguistic unity.”

Indians have debated the place of English since at least 1835, when the British polymath and colonial administrator Thomas Macaulay first opened Western education to natives. To its foes, the persistence of English among Indian elites is a travesty that disfigures Indian society more than 70 years after independence. In reality, the language is a boon, not a burden. English gives India an economic edge in a competitive world. It also keeps a dizzyingly multilingual country together by warding off the threat of Hindi imperialism.

First the nativist case: In no other major country do leading businessmen, public intellectuals and movie stars often speak to each other in a language not their own. An unhealthy obsession with English as a tool of social mobility—including among poor parents who don’t speak it themselves—is producing a generation of semiliterates unable to express themselves clearly in any language. Some activists decry the Indian love affair with English as a mark of “mental slavery.”

This argument packs an emotional wallop for those who feel excluded by English, but it’s misguided. For starters, it’s a stretch to call English a foreign language when millions of Indians have spoken it fluently for generations. The British Council estimates that India’s 125 million English speakers make it the second-most spoken language in the country, behind Hindi but ahead of Bengali, Marathi and Telugu. This also makes India the world’s second-largest English-speaking nation, after the U.S.

The economic case for English is familiar. According to EF Education First, one of the world’s largest private education companies, India’s “moderately fluent” English-speaking workforce places it alongside such advanced economies as Italy, Spain and South Korea (but far behind the “very high proficiency” Netherlands, Scandinavia and Singapore).