I'm just brainstorming and I apologize if this idea has already been discussed. But what if a group of marauding ex-zeks or some other bad guys happened to see the tent, which was glowing from candles used by the hikers. The assailants quickly hatch an idea to take the hikers back to Vizhay or Ivdel, contact the university hiking club, and demand a ransom for their release. They demand that a couple of the hikers come outside so that the situation can be explained. As the expedition leader, Dyatlov would step outside with perhaps Zolotaryov. A fight ensued and soon all the hikers hurried out of the tent and joined the fray. But as the bad guys were getting the upper hand, the hikers disappeared in the darkness as they began down the slope. The assailants, however, didn't pursue them. Expecting the hikers to regroup and begin another fight, the bad guys took off. Such a scenario provides a motive of sorts. Granted this is a Most Unlikely theory, but maybe a few posters can take up this idea and make a stronger argument than I have.