I never argues with the economic exploitation in the first place for a start.
What I did think back then was that the political outcomes for the region as a result of the empire were positive for India (the country now) . I also believed in the gift of English language and railways.
Over the last couple of years, I have visited there more often and read more about the politics of South Asia. The poverty that is a result of systemic changes made by the empire. The fledgling industries were dismantled and the goal of agriculture shifted from feeding the population there to feeding the industry here.
The British era railways are really not a positive for India, they are more of a burden. Not fit for purpose, focus excessively on the old colonial outposts rather than the masses of the country. They really were never designed to be accessible for rural population. That said, 70 odd years should have been enough to sort it out but the country never managed to resulting in bulging overpopulated cities and poor rural population.
Its funny how the press and media in India dont do enough to highlight all these things and large chunk still think that there were benefits from the colonial rule. We did a seriously good PR job while leaving.