There is nothing remotely untrue about the benefits colonialism had on former colonies and the immorality of colonialism can/should be treated as a separate academic discussion. The funny thing about this is that my parents, natives of former British (East African) colonies, also say that life under British rule had its perks. The only ones calling for revoking the authors professorship are young, social science students who have watched too many civil rights biopics.
Unfortunately, this far-left crowd have also realised that universities are essentially businesses, and they -- the students -- are customers. Universities don't want the publicity associated with a potentially 'white-supremacist professor'. It's also unfortunate that the majority of writers at influential left-wing tabloids are champagne socialists who love to prop anything racial and potentially controversial.