Holika dahan: Looking for caste interpretation amidst celebrating burning of the woman?

Today is Holi -- the day to "celebrate" the burning alive of a woman, Holika, who on being told by her brother Hiranyakashipu, an Asura king, to sit on pyre with his son Prahlad, a Lord Vishnu devotee. According to the legend, Hiranyakashipu plotted murder of his son Prahlad by  asking his sister Holika, draped in fire-resistant boon, to sit in bonfire with nephew Prahlad in her lap. 

Hiranyakashipu did this to avenge his younger brother Hiranyaksha's death at the hands of Varaha, the avatar of Lord Vishnu. He didn't like Prahlad to be the devotee of Lord Vishnu, hence decided to kill the latter.

However, Prahlad’s prayers to Lord Vishnu ensured that he was safe from the deadly flames, while Holika caught fire. 

Whatever the legend, the very idea of celebrating the burning of a woman appears despicable. While there have been several interpretations of the legend -- with some stating that being an Asura was equivalent to Dalit, while others claiming Holika was a Brahmin -- the celebration of the event as victory of good over evil seems terrible. 

Somewhere it smacks of the now abolished Sati tradition (though still being celebrated as pious!), which forced women to sit on pyre on the death of her husband.

I am left wondering: Why look for caste interpretation when the issue at stake is celebration of violence against a woman?