Pure curiosity here: do musicians have this same debate? Like, when you're learning to play piano, is there a long-standing issue about whether it's easier to learn from a book or a video? What about painters, or sculptors? Actors?
If someone knows, point it out, please. But I'm going to assume that the debate isn't as heavy in those fields (again, up for correction). And I'd like to ask, Why? Is it the nature of our medium? Is it because magic's just different? Is it because of the current generation of magicians?
Would magicians 40 or 50 years ago have this same debate, if the issue were present at the time? Or is it a recent thing?
It just seems like such a bizarre issue - is it better to learn from print or from a movie. Personally, I say that it's better to learn from a good teacher, regardless of format. That a good trick is good because of what it is, not where it's shown.
There's many good reasons why you would support one or the other, but ultimately, doesn't it come down to, "I want to learn THIS trick, and it's on DVD, so I'm going to learn it from a DVD?" Or, rarer still these days, "I can learn this from a book or a DVD. I'll pick whichever has more material to cover. If they both have the same info, then I'll pick whichever I feel will teach me this particular trick better."
You could say that certain tricks are taught better in certain mediums. Danny Garcia has a 3-phase rubber band routine in his Next lecture notes, and it took me a good long while to figure out what in the world he was trying to tell me to do. It just didn't translate well to print for me - the sleights were hard to describe and best shown visually. But then, take something like Paul Harris' Art of Astonishment series - pick every trick out of that, every one, and every essay and interview, and put it on a DVD series. It would probably be pretty expensive and a bit harder to scan through to find the effect you want.
I think that a lot of points brought up about the issue are brought up on the wrong reasons. It seems to be a case of, black and white, Books or DVDs?, when instead it should be, This trick: Book or DVD? This concept: Book or DVD?
You normally find a lot more material in books for the same price as a DVD. Older material can only be found in books. You can carry a book around and read it wherever you like.
DVDs actually show you what you need to do. You get to see angles from a spectator's point of view. You get to see the performance in action. It can sometimes help if a trick was explained poorly.
You can also just learn from both as is more helpful for what you want to achieve.