Why waste money on bringing home a pathetically small and statistically insignificant pile of what is probably slightly reactive desicated volcanic sand when that same amount could be used for a flotilla of orbiters and landers to canvas the whole damn surface?

Not to mention the hype and wasted economic potential to keep the scarry sand "contained" thanks to the paranoia and psuedoscience of Barry and his ilk. In situ analysis while not as "good", will have many more samples to choose from.

At least wait till a warm moist fissure covered with a life like goop is discovered (by the army of rovers of course..) then sample IT.