As everyone knows, de_inferno is a scenic Italian countryside village map. A region of Italy that contains this type of geography and villages is the countryside outlying Florence Italy. There is also a street sign with "Via Dante" , meaning Dante Street. Dante Alighieri was an Florentian writer and poet who wrote wrote Inferno, the first chapter of the epic Divine Comedy, which describes his fictionalized journey through purgatory and hell. If you want to go deeper, you infer that the map, de_inferno is the hell for your in game player, who after a life of killing, has been trapped in beautiful Italian village, only to kill and be killed over and over until the end of time.
(I don't know if this has been done before, or if there is some other story to why de_inferno has that name, sorry in advance)
Edit: apparently the via dante sign wasnt in cs1.6 so uh, yeah oops)