How does God punish with Hellfire the one who neglects the eyebrows, even though He commanded the cleaning of armpit and pubic hair, and cleanliness is part of faith, and God is beautiful and loves beauty?

Plucking (al-namṣ) is forbidden in Islamic law. The curse mentioned in relation to it does not mean absolute expulsion from Allah's mercy. One must submit to the command of Allah and His Messenger, and it is not permissible to reject that with intellect or personal whims. The Prophet (peace be upon him) forbade plucking and commanded the removal of armpit and pubic hair. This is not considered altering Allah's creation; rather, it is something permitted by the Sharia (definition). What the Sharia forbids is not beauty, even if people perceive it as such.