A child incapable of expressing an informed preference is in the care of the state, not of anyone else. His parents are not and never were empowered to override the NHS's clinical decision in this matter.
Modern science does not work by chucking early-stage, wholly unproven treatments at desperately sick babies on the vague off-chance they might work. That would be both bad science and monstrously unethical.
Your suggestion that there was no compassion involved in this decision is, I'm afraid, absurd. Compassion was absolutely at the heart of this decision.