Mostly because, rightly I'm sure, they discuss the individual components, or subsystems common to electronics: what's a capacitor, what's a resistor, what's an oscillator, what's an amplifier.
But where they break down, for me, is they don't put it all together. It's like having your introduction to computers being nothing more than a book on data structures and algorithms.
All important, fundamental concepts, but how do you get from an algorithm and data structure book to writing your own Rogue game, which uses all of those things.
I've never found a book or other treatise that puts it all together, at least for me. Mind, I've never had any formal training. I took an electronics class in 9th grade which basically studied Ohms law and other fundamentals, and at the end I assembled an AM radio transmitter, but I had no idea how that transmitter worked, what choices were made and why, etc. It was just a kit, and more a testament of soldering and assembly skills than anything else. Same with all of those old Radio Shack kits that they used to sell.
I need a "design your own radio" course or something that works from the top down "here's a radio, here's the structure, here's how we work on each part of that, stitch them together, why use this transistor vs that one".