How is the argument based on the Hadith: "None of you should bathe in standing water while he is in a state of major ritual impurity (janabah)" refuted when it is used to claim that used water is not pure?

This is evidence that used water does not lift ritual impurity. Al-Shawkani, in "Nayl al-Awtar," responded by saying that the reason for the prohibition is not that it is used, but rather that it has become foul due to excessive use, thus nullifying its benefit. This is supported by the Hadith of Abu Hurayrah and the inconsistency of its text. It is also contradicted by the Hadith of Ibn Abbas that the Prophet, peace and blessings be upon him, performed ghusl with the leftover water of Maymunah, and the Hadith that one of the Prophet's wives performed ghusl in a large bowl, and he said to her, "Indeed, water does not become impure."