I think we are just now seeing the promise of robotic probes. These mini science labs are going to continue to become more autonomous. Just look at DARPAs great race. If all we could do is send probes that had the capabilities of the ones just a few years ago, I would agree with you. But, the promise of increased capabilities in just a few years time is pretty impressive. The cost difference of sending a probe and launching a full scale manned assault on the Moon/Mars is pretty amazing. Sending probes anywhere would have to completely stop to fund the manned program. The ISS was supposed to allow for all of this great scientific study by the astronauts. How much of each day is consumed by reasearch compared to general maintenance, and routine upkeep. The same will be true of any mission to mars. Enormous resources will be used just to keep all of the systems needed to keep the astronauts alive going. Very little will be accomplished other than leaving footprints. Seems we've been down that path before....Hmmmmm.
That said, I do want to see us go to Mars and beyond. Even if just for the sake of doing it. But, I also want to expand our knowledge of the universe by continued exploration and right now robots are our most cost effective tool.

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