How? No matter how complex, technology can always be broken down and explained. On the other hand magic can not be broken down and explained and just kinda is.
If you assume magic exists, then magic can be broken down and explained just as easily as technology...that meaning, it can be explained by someone who is an expert in it.
My inability to describe how to call down a thunderbolt using magic would be no different than my inability to describe how moving images of tiny people get inside that box in my living room...except that *I* already know the mechanics behind that. Find someone who has no concept of electricity and the majority of our culture would be magic to them.
And for those people who keep saying magic doesn't fit with Minecraft's world...I give you Notch and some of his rambling ideas
"I think the Redstone Dust (which is, and always has been the official name for the red stuff) fits fairly well with the pseudo fantasy theme of Minecraft, and it will certainly have more uses in the future, mainly for alchemy and possibly other forms of magic."
"I'm thinking you find ingredients by killing monsters (harder to farm), then you assemble them with some kind of alchemy, and attach it to items that decay when you use them. So if you manage to get a Sword of Being Cool +2, you might still want to avoid it because of the damage thing. Hopefully it's fun."
"He wants to make alchemy magic, and would use it for taming animals. No fireballs or offensive things. More fun, less war."