Why can't banks stop freezing or locking customer accounts without warning or explanation, leaving people stranded?

“Well what rubbish this bank is! They restricted our account! WTH! GOODBYE WESTPAC!”

“freezing of all five of my St.George accounts without any prior warning, SMS notification, or email alert. I have been a loyal customer for 47 years, yet I was left entirely stranded while away on holidays.”

“log into my account and it says Mac quarries ID is locked so I called the helpline and they told me that my account has been canceled and he didn’t know why And for the money in my account I have to ask the person who tr…”