there is some truth in what this person is saying.
In film photography, typically one would be forced to think more. If you dont think, you take lousy shots, wasting film and money. With digital, you can take as much as you want and get more good shots out of luck. Peoples minds change when they realize that the images can simply be deleted.

I can definately say that about myself. With film, I force myself to be a bit more careful. Think about exposure, DOF, and everything else a lot more carefully because I cannot do 5 shots of each thing as it burns away too much film.