Has it occurred to you that many bitcoin holders have been traced and beaten up in their homes after exposing how much coins they own. I do not think many people will want to expose themselves after hearing and seeing all this theft. Some may even split their coins into many wallets to avoid trace.
They are influential and powerful enough to protect themselves. They already had a lot of wealth before they invested in bitcoins. For an average guy living in developing country with limited security, this might be a problem. But for a person of their stature, I do not think that they need to be scared of a robber coming to their home and beating them up for their bitcoins.