The first para and the last could do with some surgery; they contain too much mawkish emotion. The others are very accurate.
I could cite a large number of Bengali entrepreneurs, some of whom are still flourishing, but that would not suit the vision of the post being replied, and any contrary input is likely to be ignored. The fact is, after Bengalis realized that they could lead a very cultured and self-indulgent life as zamindars, they abandoned commerce and trade, and took to living as rentiers. The rapid transition from Dwarkanath to Rabindranath through Debendranath is an illustration. It was an open invitation to the trading community of northern India to flood in, and they did. They came with very little, but were determined, hard-working and helped each other. Even today, new ventures are not funded by the promoter's own funds, which may or may not be adequate for the purpose, but by the common funds available for use by members of that sub-set.
When the British left Calcutta, still the centre of their holdings in India, they left slowly from 1945 to 1965, then very rapidly, almost precipitately, from 1965 to 1975 or thereabouts, north and west Indian entrepreneurs in the making had a field day. They snapped up British businesses left, right and centre. So what happened to the others? Why not the Bengalis themselves? After all, they had the inner track, being employees and trusted advisors in those precise companies. Why did they continue as employees and trusted advisors, but now of other Indians, of Marwaris and Punjabis?