There are frozen (or freeze-dried) corpses of climbers all over Mt. Everest, like that of Mallory who disappeared in 1924 and was found well-preserved in 1999.
True. But most humans are quite a bit less mass than a mammoth. And the physiology of humans (the fact that their limbs are almost as long as their torso) makes it much easier to freeze.
Yeah, but those guys are at 25,000 ft. These mammoths were minding their own business, eating their greens and were then apparently flash-frozen for 10,000 years.