Imagine a situation where someone asks "How does standard model leptogenesis work?" and someone comments "What about the mass of the eta-prime?"
This comment would seem to be completely off topic, and I can imagine hiding it in a state of ignorance. But the point here is that there is an analogy between the instantons in the QCD vacuum, and the instanton events in the Weak SU(2) gauge group during leptogenesis, and chirality breaking events in QCD, where we have experimental data, can be used judiciously to give non-perturbative estimates for leptogenesis with weak SU(2) instantons.
This is just a silly example, but there are lots of cases where the relevance is not apparent to the moderators immediately. Given that this can happen, I think it is good to have a courtesy period before hiding off topic comments, in cases where it is a judgement call. I think 2-7 days is reasonable, with leeway depending on the degree of off-topicness. There is no rush, they aren't doing any harm sitting there.