To say that disabled people's lives have no value is vile, but that is not what he's saying. It's the unnecessary prolonging of suffering that Ivan Illich speaks against, the pressure to do everything humanly possible to eek out any extra week on one's lifespan, even if that extra week is a miserable one spent in agony. Now that is not to say that we should just jump off a bridge at the mere sight of suffering, but rather discern how our life is meant to be lived while letting go of our need to control everything.