One word answer: EGO.

Daksha is a symbol of Ego. That’s why Shiva (in his fierce Virbhadra incarnation) cuts off his head.

The legend has it that Daksha being a King did not approve of Shiva as he was a poor ascetic but he still had to marry off his daughter to him.

The tensions boiled at a meeting when Daksha entered all stood up except Shiva in his welcome. This enraged Daksha. Daksha claimed that as he was a king, an elder, and a father in law, Shiva should have stood up and welcomed him (Daksha was a true Indian elder relative who demanded to be respected based upon age, relation and status instead of virtue, humanness, and spirituality.)

In a typical North Indian fashion he did not like his broke, unemployed and poorly dressed son in law, never mind that he was spiritually the Master of the Universe. To socially concious Daksha, he was an embarrassment, a loser of sorts.

Unless Shiva had a palace, money, good clothes, a grand chariot (they didn’t have a Merc back then), he wasn’t good enough for Daksha.

You would find a lot of Dakshas still active in the world, try attending a wedding in India.