1. Why highly qualified Ravana was nevertheless a raksasa

    Ravana was very learned scholar, son of a brahmana, very good scholar, and economically developed, but only fault was avaisnava: he did not care for Rama. So he is designated as raksasa.

    From Srila Prabhupada's lecture on Srimad-Bhagavatam 3.26.27 — January 4, 1975, Bombay