there is a massive different between the two examples you use. A writer reflects society but a book and the damage it generally can do is in no way comparable to the actions of the state.
Mind you, Leopold was a horrible person, did horrible things and the Belgian monarchy and state have only recently begun to issue apologies for their atrocities. The debate on statues is settled, except in the minds of those who glorify wrongdoing.
The other difference is agency - there exists a legal successor to the belgian monarchy and a legal successor to the powers of the monarchy in the form of the belgian state. These have power today to acknowledge and right the wrongs of the past. In contrast, Georges Remi and Roald Dahl are both dead, unable to correct their errors.
Mind you, Leopold was a horrible person, did horrible things and the Belgian monarchy and state have only recently begun to issue apologies for their atrocities. The debate on statues is settled, except in the minds of those who glorify wrongdoing.
The other difference is agency - there exists a legal successor to the belgian monarchy and a legal successor to the powers of the monarchy in the form of the belgian state. These have power today to acknowledge and right the wrongs of the past. In contrast, Georges Remi and Roald Dahl are both dead, unable to correct their errors.