The whole Dravidian Politics, from the days of Periyar, Anna and MK revolves around the atheism and anti-brahminism. So its no surprise on the standing of MK. Periyar is known to broken the statues of Ganesha to show his anti-brahminism protest.
The stand against god is taken to root out lot of bacward practises prevailed at that time - practises like child marriage, sati, no-entry to temple for backward castes. All these activities are carried out in the disguise of Hindu traditions and to effectively take into the masses - these anti-God protests are used.
Debates can go on and on, all types of expletives can be used against Karunanidhi - but the fact is - because of the Dravidian parties in TN and because of communists in Kerala - the domination of Brahmins and Nairs have become less in TN and Kerala.
So guys, cool, Heaven doesnt fall if someone says Rama does not exist or says Rama is a drunkard.