There is a historical reason for this. Religion is practiced by Doctors of Divinity and science by Doctors of Philosophy. At the time of Newton education or universities were controlled by religious doctors. After Newton Doctors of Philosophy took control of the education. Doctor means someone who is licensed to teach the doctrine. So at the fundamental level religion and academia are organized exactly the same. Only doctrine is different. In this system cult simply means an outside hierarchy organized by an unlicensed teacher. But both are cults.
That explanation sounds good but I couldn't find much on the doctor=doctrine link. This says the word comes from medieval Latin "docere" which simply means to teach. Doctrine shares the same root word as doctor, but that root word is simply the notion of teaching and doesn't have inherently religious overtones.
