The net result was that Scotland went from being one of the most backward countries on the fringes of European civilization to being one of the most advanced countries in the world. A wholly disproportionate share of the leading British intellectuals from the mid-18th century to the mid-19th century were of Scottish ancestry, and the Scots ultimately surpassed the English in medicine and engineering.
Unfortunately, most intellectuals in most lagging groups did not urge taking the path that David Hume urged upon the Scots. More commonly, the intelligentsia have promoted the path of resentment of those on whom history had bestowed a more productive culture.
A rising, indigenous educated class in 19th century Bohemia and Latvia, for example, resented having to become culturally German in order to advance. Moreover, they resented Germans and worked to get their compatriots to resent Germans as well, even though the cultural disparities at the heart of economic and other disparities were not created by the Germans but by the Romans, centuries earlier, when they invaded Western Europe and put the stamp of their culture on that region.
But explanations of group differences based on historic or geographic happenstances do not provide emotional fulfillment. Some preferred theories of genetic differences and others preferred seeing the poverty of some as being a result of the sins of those who were more prosperous.
Multiculturalism enshrines the sins and grievances approach-- and paints the poor into a corner, where they can nurse their resentments, instead of advancing their skills and their prospects. The beneficiaries are politicians and race hustlers.