Commenter in this branch put it all together just right. Also Dyatlov notes all industrial disasters was attributed to personnel error in Soviet Union, no matter which real reason it was, for political reasons.
I'll let myself add some reasoning about accusations against Dyatlov. Even if he violated some instructions (it is still not so clear), environment and way operations conducted in SU (and maybe in some modern countries too) implicitly require that. Management requires real results, not obedience to rules and instructions. Senior personnel has to deliver what is expected from them no matter how. But if something goes wrong, negligence to rules will be formal reason to blame. So, there was no evil layman who got himself near top of hierarchy and made evil decisions. All hierarchy consists of people who was installed at their positions for a reason and they do what is expected from them. Otherwise, replacement occurs.
Basically, if you replace in this situation Dyatlov with somebody of same rank, outcomes could be eventually same or even worse.