When you and your wife have sex, do you close the curtains?
Now, occasionally you might get some pervs, but in general it illustrates the point that privacy is a good thing and we should be jealous about guarding it!
It is this small-team approach that, of necessity, results in important capabilities being left out of the first release. The payoff, though, is that Steve ends up with a central core of perfectly-integrated functionality instead of a rambling labyrinth of disjointed “features.” This design framework is so well conceived that it can be built upon for years, even decades, without being stripped out and restarted. Compare that with the history of Windows, with false start after false start, resulting in their repeatedly beginning design anew.
People like the digital ones because they don't just amplify, they selectively filter to you get the most useful frequencies. I don't know the physics, but I suspect it's far more advanced than a simple equalizer.
It probably isn't. Equalizers or adaptive equalizers (for when you don't know your channel characteristics, which you do in this case 'cause you can measure the ear's response first) are straightforward systems. It's basically a digital filter that inverts the channel's frequency response. Pop open MATLAB and you can have one up and running in minutes. There's plenty of source code on the 'nets for generating a equalizer for a DSP or FPGA. The hardware/software isn't hard at all. That only leaves testing and regulation for attributing to the high cost.
Take an astronaut to launch.