I don't take any issue with the sentiment; they want to advance specifically commercial domains by incentivizing them to accomplish moonshots.
The problem I have is that the moonshots (quite literally in the case of the Google Lunar XPRIZE) are so ambitious that the only people that have the resources to even come close to accomplishing these goals would never be interested in prize amounts this small. They would almost definitely end up losing money with the purses the size that they are and quite honestly winning an XPRIZE just doesn't carry enough prestige to counter the capital losses.
The amount of R&D needed to get a robotic avatar to the level proposed here is staggeringly larger than $10mil.
I just don't see the point.