Not all Empires are equally malevolent. The late British Empire (Victorian and on) was arguably somewhat benevolent. Racist, patronizing, exploitative, and occasionally still brutal, but no sane person would compare British rule in India with Japanese rule in Manchukuo, or even with Belgian rule in Kongo. During the late colonial era, the British (and the French) worked hard to improve the condition of their subjects, and the British at least allowed some degree of native participation in government and contemplated the eventual liberation of their colonies.
There can be no doubt that most former British colonies are vastly better off today than they would have been without colonialism. From Belize to New Zealand, Britain introduced technology, educated natives, built railroads, created middle classes, and gave the laboring masses a degree of freedom and respect which, however small, was much greater than what they were allowed by native despots. And, after all their investments, the British (and French) granted most of their colonies independence rather peaceably, compared to the savage tenacity of, say, Portugal.
One simply cannot imagine Japan acquiring the accumulated suite of the highest Western virtues (if egalitarianism, respect, and compassion are virtues), built from the roots of German tribal society over a period of two millennia, in a matter of a generation or two - let alone while Japan had never had to deal with a serious challenge from a foreign nation, or even had much cultural contact therewith.