[Phantasm]

Originally Posted by David Johnston2

Yeah but that's pretty much beside the point. Is there a reason why the detailed exploration can't just be done with robot probes that move so much faster than people?

Time constraints (the probes don't have sixteen to thirty years to spend in a system mapping each planet encountered before returning home, as they are unable to send the results back in anything resembling realtime; remember, it took us months to get all the data New Horizons recorded over a few days' flyby past Pluto, and now factor in "no FTL radio" over dozens of lightyears), coupled with a lack of truly volitional AI (in this setting, volitional AI essentially must be "grown" rather than "programmed" and that takes time, and is generally reserved for the one race of sentient robots with TL12 computers, though the occasional droid may develop into one) for the probes. At best, you've got non-volitional AI with pre-programmed responses ("if it's a threat[list of threats], spin, engage thruster to reverse course, and enter hyperspace headed to [these coordinates]", etc). And in no case can the on-board computer interpret the data.

Plus, while they are faster in hyperspace, the probes themselves may not be moving at speeds that can match those reached by manned craft; you're more likely to have basic maneuvering thrusters and a limited delta-v on a probe than you are a full-fledged reactionless engine like those mounted on a hyperspace-capable SWACS craft. Probes are supposed to be fairly cheap; reactionless thrusters aren't.

Clear as mud?