I sympathize, but…
1) McGonagall has grown since the Roles arc, and is more likely to think about the consequences of her actions, now.
2) She is more maternal than Dumbledore was, he wouldn’t have necessarily thought that way and he was in charge after the first dark war
3) Time—it is much more obvious to McGonagall how the newly-orphaned students will react and will be treated, then it would have been for her to realize how much of a target Neville was
4) Similarly, the likely treatment of death eater orphans is probably much more physically severe than what Neville goes/went through
5) Up until the Self Actualization arc, Hogwarts did not take bullying seriously. Many real-world schools still don’t
I sympathize, but… 1) McGonagall has grown since the Roles arc, and is more likely to think about the consequences of her actions, now. 2) She is more maternal than Dumbledore was, he wouldn’t have necessarily thought that way and he was in charge after the first dark war 3) Time—it is much more obvious to McGonagall how the newly-orphaned students will react and will be treated, then it would have been for her to realize how much of a target Neville was 4) Similarly, the likely treatment of death eater orphans is probably much more physically severe than what Neville goes/went through 5) Up until the Self Actualization arc, Hogwarts did not take bullying seriously. Many real-world schools still don’t
Sure. Doesn’t help the victims in any way, Truth and reconciliation are nice, but that is not what is happening here.