^^ What he said
While gold in your possession can be lost or stolen if you're careless or unlucky, if that happens it is your fault, and should some one try to steal it you at least have the opportunity of defending yourself against such an attack. A piece of paper claiming ownership is not the same as ownership. All it takes is a letter to revoke that ownership and there is pretty much sod all you can do about it. Possession, 9/10 ths and all that...