Are 12000 dpi laser mice overpowered for the human wrist?

So I've seen laser mice become more and more powerful over time, with newer models supporting increasing levels of "DPI". The latest ones I've seen support up to 12000 dpi.

But what does this mean? Are humans with their wrists and hands actually able to place a mouse in 12000 different positions over an inch? Are humans able to move their wrist 2/12000 of an inch to the right and know they have not moved it 1/12000 of an inch to the right or 3/12000 of an inch?

Assuming that I am correct that no, humans are not able to do these things, why do mice manufacturers keep making mice more and more powerful?

To contrast with the approach Apple has taken with its ppi on its screens, it claims that its "retina display" technology is overpowered for the capabilities of the normal human eye and it packs only 220 pixels per inch (see http://support.apple.com/kb/HT5266). The approach mice manufacturers are taking seems to have taken a break from the physical capabilities of the human form.