It went beyond rude. Lot had guests and some of his neighbors demanded he hand them over to be raped. Hence the confusion...but it was an exaggeration of poor hospitality.

In a harsh environment such as a desert, you treat guests well because next time it might be you, and if you are left outside you could die. So hospitality was vital. Same in extremely cold environments. Western Europeans from relatively mild/nice climates don't quite get it.