I largely agree, but I do think fantasy-story magic differs from our world's physics in one significant way: the laws of magic tend to resemble human psychology much, much more than our physics does. The opening quote of this post is itself an example: to practice their craft, Pratchett's witches have to negotiate with gods, which--real and mundane as they may be--presumably have beliefs and desires that bear at least some similarity to human ones. And while it's occasionally a nice shorthand to refer to physical entities as having beliefs and desires (look, the charge *wants* to go that way/this amplifier *knows* where ground is), the mappings are very rudimentary, and they aren't even a very accurate way to look at the picture.

Even when magic doesn't involve actual gods or godlike beings, it usually interfaces much more "nicely" with human psychology than real technology does; the process of casting a spell often depends in some way on the caster's emotional state, and spell effects can be structured around intuitive concepts with apparent ease (say, a curse that affects subsequent generations of a family--a group of entities that is very difficult to specify in physical terms). Granted, our real-world technology could conceivably advance to the point where it works something like this, but it's still an important fact that it doesn't, and can't, work that way _now_. Until we make some giant technological leaps, being an engineer or physicist is not going to be much like the typical wizard's experience, where psychology really matters and one's emotions have intricate effects on one's results.