Also, with a bank you receive notifications for each transaction when your card is used so you are alerted if there are transactions taking place without you being present which gives you time to stop the card. With bitcoin there is no such option, yet, and you will in most cases only realise that your funds are all gone when your card is being declined and or when you check your wallet.
Depending on which debit card you use, there are SMS notifications for every transaction if you want. Not all of them have it available though, that's true.