All About Pocket Knives

Why are these left unsharpened from the manufacture?

Because it’s designed to stab .

true on intent to be used as stabbing weapons, but I lean more into this explanation. That and because its cheaper, and these days it seems the makers are just not as interested in providing quality products. But primarily this as maybe an excuse not to do the extra work and to meet regs.

"Safety/Production: Because they are popular for collection and display, many modern reproductions are left unsharpened to avoid accidental injury or to comply with safety regulations."

I haven't met a stiletto recently that I'd use as an EDC or as I would most knives, but they are fun and pretty !
Sorry if I sound jaded, spent some high dollars on unsharpened, wobbly, less than fully extended "high end" Italian knives , my Italian forefathers are letting me down

Some of the earliest stilettos were designed to be sharpened. Most were not.
Most of the 1950s knives were never designed to be sharpened. They were designed as stabbing weapons. It had nothing to do with cost or regulations.

I only have two Italian ones and both are F. Beltrame, I sharpened both.

I have a Renzo Pascotto that was never sharpened what's so ever, it's as dull as the day is long!