Monuments offer interpretations of the past and play an outsize role in shaping historical narratives and shared memory. In the service of remembering the preferred narratives of their creators, they also can erase, deny, or belittle the historical experience of those who have not had the civic power or privilege to build them. Where inequalities and injustices exist, monuments often perpetuate them.National Monument Audit – Monument Lab (page 25)
For those monuments in question, they are not just about reimagining the past; they are about reshaping the present and future into something amenable to the colonizer. Contrary to the argument that these monuments document history, those in question serve to erase or deny or belittle the subjugated and promote a fabricated narrative that elevates the stature of the colonizer and perpetrate harmful myths. In this context, it is hard to justify keeping a monument that is essentially propaganda.
Furthermore, as noted previously, monuments play a supporting role in a much wider landscape of techniques that includes education, legislation, religion, etc. that can shape national identities and collective memory, influence public opinion, justify actions and influence future decisions.