“[The Fed] added almost $1 trillion new credit to the financial world in about two months.” – not exactly
“[The Fed] traded Treasuries for the toxic waste of poor-quality mortgage-backed securities” – more accurately reducing the liabilities not adding credit.
Read these two statements very carefully and you will see where a huge mistake is made. Are you adding credit to the financial world when you buy poor-quality mortgage-backed securities? Or are you reducing the banks liabilities? This is a huge difference because both will help balance the account sheet of the bank, but one supports inflation while the other does not right away.