Why not? They are smart people. It's troublesome that smart scientists and engineers are largely guided by paycheck size and "exciting"ness, I stead of actual benefit to society or individuals. Scientists make lots of money developing chemicals, for instance, with little to no concern over whether the chemicals are positive or negative. They are just doing a job. Everyone at SpaceX is likely a true believer, but as I've pointed out, they don't like discussing the realities of the mission beyond whether they CAN do it or not.