Actually, DVD's still sell in the tens of millions every year in the US alone. Hundreds of millions worldwide.
No, DVD's are not "old" tech, not yet anyways. Apple is simply doing away with a competitor to the iTunes store, plain and simple.
The market is shifting towards online digital media. Apple killed off the floppy drive when it was still being used by every other manufacturer. The only time I ever use the DVD drive in any of my Mac computers is to rip movies to a hard drive and stream them locally. Heck, I bought an external Bluray drive to rip movies to a hard drive and stream them. All other times, the DVD and Bluray drives is sitting not being used. When I travel I have movies stored on my iPad for the kids to watch. Point being, since most of the time I don't need the DVD drive, I would simply buy an external DVD drive and hook it up when needed. I know that everyones usage vary.