The argument proves too much. If the fact of having a colonial history disqualifies a nation from making any judgment about reparations claims against it, then no resolution to the question is possible, because any settlement would require the agreement of the former colonial power. The argument is structured to make disagreement impossible, which means it is not an argument at all but a demand for unconditional capitulation.
The same logic, that those who benefit from a wrong cannot judge claims arising from it, applies with equal force to the claimants. Caribbean governments have an obvious financial interest in the reparations claim succeeding. If financial interest disqualifies judgment, it disqualifies both sides equally. The argument cannot selectively apply the conflict of interest principle to only one party.
The claim also mischaracterises the nature of the objections to reparations. The arguments on this site are not that Caribbean people are wrong to feel aggrieved, or that the history of slavery is less serious than they say. The arguments are specific, evidential, and legal: that the proposed mechanism does not work, that the causal chains are not established, that the legal foundations are not sound. These are arguments that can be made by anyone regardless of their ancestry, and they can be answered on their merits without reference to the identity of whoever makes them.
The accusation of colonial attitude is also remarkably effective at closing down self-examination among its targets. British people who raise legitimate questions about the reparations model often retreat from the conversation rather than be labelled as colonialists. This chilling effect on debate is not an accident: it is the purpose of the accusation. A serious engagement with the reparations question requires being able to make arguments without having one’s motives pre-emptively characterised. The accusation prevents that engagement and thereby prevents the very conversation that might produce genuine understanding and reconciliation.