The principal investigator for the Mars rovers said that if he were on Mars he could do in 45 seconds what the rovers do in a day.
I think you're talking about Steve Squyers, the principal investigator for the Mars Exploration Rover missions. He's a really smart guy and he's not wrong in his statement you're quoting. To wit, Apollo 17 astronauts collected about 110kg of lunar rocks during 22 total hours of EVA and drove a grand total of 36km while the Spirit rover only drove about 3.6km and examined (but did not collect) about 25 rocks over the course of 8 months.
However you simply cannot use this data to imply that humans sent into space are magically more productive than robotic probes. A field geologist would need to do a day's worth of work in 45 seconds on Mars because they would die of asphyxiation in about three minutes. To prevent that they would need to carry around their own oxygen. To keep it from floating free it would need to be contained in some sort of mask. The freezing temperatures would then kill that geologist within a few hours so instead of a mask they would need a whole insulated airtight suit. To keep from dying of dehydration within three days they would need water. Now that they would survive the night they would need food or else they would be ineffectual in their explorations after a few days and dead of starvation within a few weeks.
From there it only gets worse. In order to do really interesting work the field geologist would need some tools, not the least of which is a camera and a transceiver to talk back with Earth about their findings. To do anything more complicated would likely require more complicated tools. To keep these out of the elements (dust storms, intense UV radiation, Martian attack, etc) the field geologist would likely need some sort of habitat.
So really the field geologist needs literally tons of logistics behind them to do the work of an automated probe. That's a lot of non-mission specific mass to send to Mars just to support the single capable field geologist. With the extra mass comes expense and added complexity of the whole system.
Why not skip the extra bullshit and send more automated probes to Mars that were designed by an army of field geologists? You could send a dozen such missions for the same cost as a single manned mission and end up covering every major geologic region of the planet. You could also fill up its orbit with a squadron of multispectral imaging satellites that could relay data as well as collect their own.
I understand the desire to plant a human being on Mars but at the same time the pragmatic part of me interested in the actual science would rather see a dozen automated missions sent first. Putting inanimate objects in space is Hard, putting living things in space and getting them home still alive in Very Hard, putting people on the surface of other bodies is Extremely Hard, and putting people on the surface of other bodies having them do useful work while there is a damn moonshot (pun intended). Getting them home from said body is a "nice to have" and a minor miracle when it occurs.
Humans can be more effective in some places than robots but they're not necessarily more efficient than robots. If you've got limited will/funds the robot is usually the better option.