I co-own a small DI house and I can say with pride that I agree with a lot of what John Bailey is saying.
I got interested in DI because I saw it as a way to make the life of a cinematographer a little easier. With well-shot negative, we could more quickly and less painfully acheive a look.
But I'm shocked at what I see at the multiplex often. Burned images, insanely manipulated images. Much of what's out there seems to be OVER DI-ed like one giant photoshop session. Its that old saying, just because you can doesn't mean you should.
I think DI has to be used very carefully and with a soft touch. Its there to make fixing things easier or there to fully realize a look that was intended from the beginning, but not there to replace the cinematographer. At my shop, we ususally say, you can make BAD look OK and OK usually look GOOD, but you can never go from BAD to GOOD.