Currently, it's hard for people to get loans. So if rich people buy bonds, the banks won't lend out much of the money. Interest rates are so low, banks wouldn't make much money on the loans, so there's not much incentive to make more loans. And since the inflation rate is hovering around 0, the bank isn't really losing money by just sitting on it, There just isn't any incentive for the banks to make a lot of loans.