They are not illiterate people or stupid people. Malibu temple president Dr. Mahadevan, said that though the granite idol installed there had not taken in any milk, the number of calls of inquiries had run into the hundreds. The priest at Bochasanwasi Swaminarayan Sanstha temple at Whittier too, said that their idol of Ganesha had not taken in the offerings. Realists however point out that the milk is merely oozing down from the belly to the knees, leading to a drain. Milk is white they say, marble idols are white, the base is white and therefore camouflaged.
Rationalists theorize it was a process of capillary action or absorption.
According to Lawford Anderson, a Professor of Geology at the University of Southern California, milk could be soaked onto a stone if it is porous. And of this there can be no doubt, the world has learnt about Lord Ganesha.