Also its not good to point out always to those homeless that they automatically stole it since not all people in that status do that crime just to have money to buy food. Lots of them fight fair and try to earn simple living.
So there's huge possibilities that the assumption of these gentlemen out there is right because we know Satoshi is so famous and provably people around it have an idea about Bitcoin and who has been represented by that statue.
The statue is made of stainless steel and corten blocks which means the materials are not expensive. Selling it will be difficult since the news about the crime have spread. Only the thief/thieves know the reason for this shameful.
We cannot also write off the possibility that it could be a Bitcoin hater that is unhappy with the growing popularity of Satoshi and Bitcoin. Someone might also carryout this act because he want to be popular (these days people do lots of stupid things for popularity)
Satoshigallery the group behind the statue is offering a 0.1 Bitcoin to anyone with useful information that can lead to its recovery.