Nothing naive about it. You either sacrifice, or you don't. They chose to be part of the system and let those people melt and rot alive, for fear of the alternative: charged with murder.
This is an oddly absolutist stance. Euthanasia, being allowed to die, ending a patient's suffering, it's a complex and sensitive matter. It's easy to say now that those stricken with ARS should have been allowed to die before they endured too much pain, but the laypeople and those in the ground in Chernobyl knew very little about the effects of radiation sickness at the time of the disaster and - as we see with Vasily - genuinely thought they would get better. In fact, they knew very little about what was actually happening at the power plant. As I've said numerous times in this thread, the point that the series tries to make is that any information concerning the disaster was contained and deliberately muddled by the Soviet Union. Thirty years on, we still don't have the full picture. I can't imagine what it was like within a week of the accident.
If you must know, I'm a huge advocate for allowing people to die on their own terms, or when it's for the best, or to shorten a person's suffering. If you pressed me hard enough I'd say existence is a curse that we all deserve to be free of. My granddad's five years deep into vascular dementia and we've recently moved him into a care home - he's badly withered because he refuses to eat, he's suffering with intense paranoia and incontinence, and he can't remember his own name. Pretty soon he'll die, either by stroke, heart attack, or choking to death because he's forgotten how to swallow. If there was a way to end his life tonight while he slept, I'd take it in a heartbeat. Keeping him alive is pointless. The care staff at the home he lives in, though, have a legal obligation to give him his medication and feed him. To what end, though? His medication won't make him better, it'll just mean he's artificially withered, paranoid, and incontinent for longer than necessary.
But am I angry with the care staff for "choosing to be a part of the system"? Absolutely not. As far as the care staff are concerned, they do what they do to make my granddad's last few months a bit easier. Are they naive for thinking that's even remotely possible? Definitely. But do I expect them to stop giving my granddad his medication out of mercy, and is it worth getting so worked up when the end result is the same for my granddad whether it happens this week or in five years? No. I think you have to apply this same begrudging acceptance to the situation at Chernobyl. It would have been easier for the nurses to euthanise those ARS sufferers but the legality of euthanasia in the Soviet Union is sketchy. Everybody involved was either acting under direct orders or doing the best they could in the middle of complete chaos. Those affected by radiation sickness dying so slowly and painfully is an awful thing to imagine, but I'm not sure you're directing your anger towards the right people.