History is an interpretive discipline. It is therefore subject to revision and fashion, so we cannot completely disregard those factors, It is most evident if you read Victorian or Edwardian histories of our period, as you often catch a glimpse of the dominant poliotical theories of their day. Modern historians tend to regard liberal democracy as the norm and colonialism and imperialism as abnormal. Remember, Napoleon made himself Emperor. He was clearly ambitious, a fact he made no effort to hide. It's not surprising that his own characterisation of himself, as benevolent and fatherly dictator does not play well today. He saw himself as a Ceasar, and regarded his own historical legacy in that light. There are very few (if any) openly imperialist authors who would share his opinions.

I therefore think your impressions you are largely a function of the books you read and the forums you hang out on. There is plenty of opprobrium heaped upon British colonialism and imperialism, but as it's zenith was later, you find it elsewhere. There is even more on European colonialism generally but as this extends into the 20th century, you will find that criticism elsewhere also.