It's not a technological imperative that drives the resuscitation of so many patients who (if you had asked them while they were of sound mind and not about to die) would rather not have been resuscitated, it's a philosophical imperative. Most doctors, in my admittedly limited experience, are biased towards doing something rather than nothing. Or - rather - biased toward the assumption that taking a positive action is more helpful, because more active, than doing nothing. But sometimes doing nothing is not doing nothing at all. Letting someone die can sometimes accomplish more than a breathing tube or a defibrillator ever could.