I just watched Neil DeGrasse Tyson's word on the subject yesterday (https://www.youtube.com/watch?v=wNxnCzz5oQE) and he quite agrees with you: "We're going to Mars in 20 years" is not what NASA should be about. NASA (and other space agencies) should strive to make space re-enter our culture so its benefits can rain on all aspects of our lives. In order to do that his proposal is to double NASA's budget and focus on building a suite of vehicles able to transport whatever they want. Kind of like the space shuttle but for longer distances, such as the moon, asteroids, Mars, Lagrange points... If you have perfected a space vehicle, going to Mars is about adapting that vehicle.