As others have mentioned, there are times that a debit card meets someone's needs in ways that a credit card does not. After a move (and my reluctance to sever ties to my original financial institution) my only "free" source of cash access was obtaining "cash back" at the grocery store, with debit card purchases. It sure beat cash advances with a credit card that charged transaction fees and did not allow a finance charge grace period for cash advances.
When considering rewards programs, some debit card issuers (Chase is one) are providing rewards programs, but it still doesn't tempt me to switch from my credit card to my debit card. The only thing I use my new debit/ATM card for at this point is to obtain cash at the ATM machine. On a side note, I found it interesting that when we opened the Chase account, we were not allowed to opt out of receiving the card. My husband never uses it, so we shredded his and I guard mine with my life. :-)
For those who don't keep a generous balance cushion in their checking account (and keep meticulous records of their debit card usage) I would suggest shredding their debit card. I'm thinking of the youth in my life who tend to use their debit cards at fast food restaurants multiple times a day and end up purchasing some VERY expensive sodas when their account becomes overdrawn. I would much rather see them use a credit card ... IF ... they can be disciplined enough to PIF on time every month.
Actually ... I would much rather see a system in place that doesn't encourage all of us to use financial payment methods that incease the cost of the merchandise that everyone ends up paying for. Technology is great ... but with everything ... you pay the price for it. :-(