Let's enter a hut! Whether we're invited or not! I would imagine that the point of sinking the floor of such a hut a bit into the ground would assist it in maintaining desirable temperatures in summer and winter...plus, anything that might cause an invader to stumble upon unwanted entry would be of benefit to the hut's dwellers, as such clumsiness would embarass an attacker, giving the defender the moral high ground and ability to shame said attacker, who would have to depart unfulfilled, lest he be laughed at.