Why are we comfortable doing a job?

I have seen people are by default always looking for a job only. Even though they might crib about money, timings, bad boss and what not, also they might even have elaborate plans as well for their venture, however still not even 1 among 100 of these really materialize. It is very hard to leave job even though it is inherently so very bad. Actually the answer lies in the deep human psyche.
Maybe in the deep gone era of primitive human population, it was very difficult for the hunters of the society to hunt for food and stuff and the others who were dependent on them, had it very simple, just sitting easily and waiting for food to arrive. Although they might not be respected much but still got enough food for survival without much effort, decent bargain if we could say. We are still the same in many aspects. We are very much happy if not confronted with challenges. Who would want to tread an unknown territory, it is certainly not easy.
Job comes with all these benefits. There is a certainty of work. There is limit of work. There is no undue responsibility of others. You always have somebody else to blame. It is lot easier to give the deciding power to others for you. This saves you from the responsibility and hence answerability. This shall also explain why majority of the people in society are followers as well instead of leaders and you see so many lectures, seminars and workshops for developing leadership. Nobody teaches to be a follower!!!