This is such an asinine argument against loanable funds theory and is equivalent to saying, "Actually, it's the other way around. People drive their cars first. Only then do they worry about the amount of gas they have in their tank." You see the same kind of nonsense from MMTers who use their confused understandings of accounting identities to justify their policies. In addition, the notion that entities that have excessive amounts of wealth, ie they have accumulated capital through successful investments, would be less likely to put their money to good use is silly. It's not capital accumulation that leads to bubbles. Historically, it's been caused by an influx of money not supported by production due to currency debasement, precious metals stolen from the new world flooding into the Holland, various precious metal rushes, excessive printing of paper currency or bank money, or suppression of interest rates.