Some accounts will do that. Some will instead pay a legitimate looking transaction and then charge the account-holder a penalty or hold or grab funds from other accounts. If enough bad (fraud-filed) paid or unpaid transactions are made I suspect there would be a risk of being refused further cards or accounts. So while I agree with you it's a better option than nothing, I think there are still downsides.
Either way, glad you haven't been victimized!
Maybe you have different rules in America the bank here advised me to do it this way to prevent any fraud of my card. The banks here will cover any losses for fraud on your accounts. I have other CCs that I use every day, this one is just for on line purchases where I am not sure if it is safe.
Yes I think I am very lucky and feel for those who are having this problem. Hopefully the guide will help others to protect themselves.