I think his point was more along the lines of, why aren't you using an actualcreditcard instead of the debit card? Now, I use my debit card too because I currently don't have a good rewards card, and it helps me budget better knowing it is coming directly out of my account, but if it is stolen (physically or otherwise) or mis-charged or even just used for something you end up returning, you're dealing with actual cash out of your account, not "imaginary" money so to speak. If a debit card gets stolen your bank account can often get seriously fucked up, making it difficult to pay bills while things are frozen and sorted out, so *most* people recommend not using a debitcreditcard if at all possible.
Again, that's not what I do, but I hope to change that soon, and having read this board long enough, I'm fairly certain that is the overwhelming viewpoint of the "smart spenders" here.