Other than feeding their curiosity and invading other bitcoiner's privacy, maybe the people who are monitoring BTC movement from "ancient" wallets like that, whale wallets, or hacker's wallet, fear of big dumping on exchanges. The 1,000 BTC may not be that significant but I'm quite sure the market will have a reaction if the coins mined by Satoshi Nakamoto [NOT CSW], or other wallets with huge BTC holdings, would suddenly move.