When the Karnataka Unification struggle took a political turn, the movement’s political responsibilities were taken up by the Karnataka State unit of the Indian National Congress.
More than 10,000 Kannadigas from different parts of Kannada speaking regions marched to the 1920 Annual INC Meet held at Nagpur, along with as many as 800 pro-unification leaders and made a strong case for the establishment of a separate state unit of the Congress Party in the Kannada speaking regions, which was under almost 20 different administrative units.
Karnataka Pradesha Congress Committee was thus formed the same year, and four years later, the historic conference was hosted by KPCC itself in Belagavi, Karnataka and was presided over by Mahatma Gandhi.
Karnataka Pradesha Congress Committee was the political flag bearer of the Karnataka Unification Movement, and when Karnataka wasformed, similar to what happened in India, KPCC took over the administration of Karnataka as well. Indian National Congress has ruled Karnataka for a very long time.
Later, when Janata Party revolution was at its peak in India, there were pretty great leaders from Karnataka too, who were immensely popular, the likes of Ramakrishna Hegde. During this time, Janata Party had its presence in Karnataka.
The Bharatiya Janata Party also slowly emerged at the dawn of the new millennium, again similar to Indian Politics, and today. Karnataka is the only state in South India, which has significant political presence of BJP. Basically, Karnataka politics has been a mirror of Indian politics- the landscape has changed over the years almost the same way it has in Indian politics. Today, due to the extreme lack of internal democracy in national parties, and lack of autonomy for state units, the people of Karnataka are bearing the brunt for having continued to give the responsibility of administration of the state to the no longer internally democratic, autonomous Delhi centric national parties.
One more possible reason is because no popular personality from the field of art and entertainment tried his/her hand in politics. The wait is of a formal introduction of Karnataka centric regional parties.