busprof

I wouldn’t say drains reserves and reducing credit leads to a decrease in the money supply…
When the government conducts open market operations (ie: selling securities) they are decreasing the money supply in the economy, which ultimately leads to a reduction in the amount of money banks have to lend, thus decreasing the availability of credit and causing an increase in IRs.
As for if nobody wants to buy them… just think of that as a scenario that doesn’t happen; what the Fed sells, banks always buy.