I bet it was not because of the incredible sensitivty of its spectrometers, but rather the images.
The images – the human part. The part when photons, electron, electromagnetic waves and silicon conspire to share with us something in the language we know – the language of our senses – as if we were there.
Science, discovery and learning have everything to do with connecting to people – otherwise you might as well stick it all in crates and ship it to the warehouse scene at the end of Raiders of the Lost Ark.
James Cameron uses science as a starting point and technology as a tool – he knows, possibly better than anyone alive, the value of not just making discoveries, but of sharing them with everyone.
A duplicate camera is needed to get human-like stereo vision on the rover – two cameras = two eyes = 3D. But camera #2 adds cost, weight, and cost, as well as power consumption and more failure points. Believe me, engineers hate that, especially when there are milliwatts of power to be budgeted to achieve maximum science.
But what we get is something unique. The cameras will allow anyone – that is anyone without a PhD in exogeology – to be on Mars. The cameras are at human eye level, and spaced like human eyes. when you look at stereo images from them, you might as well be standing next to the Rover. With the upcoming ubiquity of 3D display, and an expected lifetime from this rover of 5 or more years, and with the realization that NASA is about wonder as much as science, JC’s lobby seems a valid one.
Expect these 3D images to be included in science museum interactives to be shown before 3D movies, and to appear on parallax-gated 3D game displays.
JAXA, the Japanese space agency showed with recent highdef moon footage what we miss when we put every bit of nadwidth towards science and leave nothing to outreach. Both are necessary and both support one-another.