pontifex01, I think part of the value of the slow taper is like I said it gives you a chance to work on regaining your natural coping mechanisms, which takes longer than it does for your brain chemistry to physically recover from the drugs themselves, you absolutely can taper more abruptly in a short space of time without it being dangerous but it makes it more likely you'll end up back on them again, i think.
some drugs are metabolised and out of your system a heck of a lot quicker than people imagine, nicotine for example, in a way that shouldn't sustain an addiction if there was no other aspect to the habit, in which case that needs to be dealt with... I don't think it's as simple as just stopping the drugs.