We have some pretty capable little explorers on Mars right now, and should we see some opportunities that are so compelling that we are willing to sacrifice one if necessary, that decision can be made with plenty of time to contemplate and weigh the benefits and costs. If we sent humans to Mars with current or near-future technology, we would gain flexibility and autonomy, but lose the advantages of robotic exploration, including lighter payloads (fuel is expensive, but lofting that fuel to orbit is WAY expensive), modest shielding requirements, and the ability to use fuel-saving gravity-assist trajectories to get the probes there without a lot of reaction mass to throw. Getting to the Moon was a walk across the street compared to getting humans to Mars, and the Apollo astronauts did not stay there long enough to stress their life-support and power systems.
I love the thought of space-flight, but at our level of technology, I would prefer that we fund numerous robotic explorations instead of gutting science for the sake of the "gee whiz" accomplishment of getting humans to another planet. Just my take on it. BTW, I grew up with the Mercury, Gemini, and Apollo missions in full swing and have an "autographed" picture of Buzz Aldrin that was certainly auto-penned. He was flying combat missions in Korea when I was born.