Angels had a one shot deal - unlike man, they don’t have plan of salvation. Mankind on the other hand had two chances to be with God forever – the garden and the gospel. Infra-lapsarians place a lot of weight on Adam’s fall – the fall is the reason any man is reprobated1. Thus infra-lapsarians see God as a just judge in reprobating sinners. But what carries this weight in the case of reprobate Angels? It would seem justice cannot play the vital role in their reprobation that it does in the case of mankind, if it can play any role at all. And thus with respect to God’s character, they lose whatever ground they might have gained via going with infra-lapsarianism over supra-lapsarianism.
1 Reprobation may be understood as either passed over and not elected or actively reprobated. Infra-lapsarians tend to describe reprobation in terms of being passed over, but some infras do hold to double predestination. Infra-lapsarians say the reason anyone is reprobated at all is due to their fallen sinful state while the reason this person is reprobated and not that person is simply due to God’s will.