Debit card is your money which you are spending and it is not debt; it our asset we are spending.
Explanation:
As we are using our debit card means; that we know the amount of money we have in our account. So, according the reserve we will plan our spending while doing our shopping.
Since we know the limit our intuition will not allows us to go beyond certain limit for which we might have planned. In other way around if we about to use the credit card mean; you do shopping without any funds which will create liability.
If we are not having controlled spending you debt will increase and it will lead you to other financial problems. So, we have to plan for a controlled spending based on our income and future spending.