When someone gets asked to distinguish Gazan Palestinians generally from Hamas, Hamas is made out to be a much more fleshed out, organized entity and they take on an oppressor role. In that vein, "destroying Hamas" would not seem to be any more an illegitimate victory condition than "destroying ISIS" was, and no one objected to that at the time. The West did not have an issue imposing a view of the war against ISIS as one of liberation, but that same war of liberation viewpoint is not applied to the war against Hamas. That seems odd, and I wonder if the acceptable threshold of collateral damage would shift if this were sold partly as a war of liberating Gaza from Hamas, rather than solely as retributive for Hamas's attack on Israel.
If the war was promoted as, we are going to remove Hamas and set up a free and independent Palestinian State (which would be one of liberation), you would see the world react differently.
But if that was offered. The war would be over very quickly, as that is pretty much what the Palestinians want.
But that isn't remotely what is going on here. The Likud party's formal stance is there will never be a Palestinian State anywhere between the river and the sea. It is not a war of liberation, or removal of Hamas, it is a war of collective punishment.