Penguinism suggests that YHWH is evil, but this statement should be justified. Here I will use general concepts from western morality to argue this claim.
First, a universal objective morality may not exist, but we can still argue that something is or is not moral, within a given framework. In this case, it will be within a general moral framework commonly used by YHWH’s followers.
Punishment is at the core of this argument. When someone receives a punishment, it generally serves one of three purposes. The first is correction. We punish in order to correct negative behavior so that it does not happen again. The second is recompense. We punish to fix damages caused by the action. The third function of punishment is retribution.
Eye for an eye falls into this final version of punishment. But even in the case of retribution, which is essentially quite selfish, there is a sense that punishment should not be more severe than the transgression warrants. This form of punishment has been discussed extensively, and even finds its way into the Talmud (Eye for an Eye).
Human limits prevent us from being able to influence reality in a way that is infinite in nature. Humans are finite beings, at least according to Christian doctrine itself. Only god is infinite, or so it is said. Therefore any transgression committed by a human must be finite, unless aided by an infinite being, like a god.
Eternal punishment, in the form of hell, becomes a punishment that violates our norms of what constitutes equitable punishment. Furthermore, it is also definitely not corrective, as it is eternal. It is pure retribution. It is reasonable to assume that a being which tries to enforce such punishment is either ignorant of it severity, unable to refrain from such action, or is willfully punishing people in a way that is wrong.
YHWH is evil, or at least a false god, because it threatens to engage in punishment that is far more severe than the transgression, and does so without any attempt to make the punishment corrective. Of course, this only works for biblical interpretation where YHWH does exist and in which YHWH is truly threatening people to eternal damnation.