There is a reason why Germans, unlike the British, are not famous for their good sense of humor!
We do (or in this case sadly did) have a few greats, though!
I'm pretty sure that telling to draft in inches adds the same "mystery" to a garment for Italian customers like using "rock of eye" does it for US customers.
So please don't get too personal, what we are talking about here is just a bloody dart (sorry, got to wash my mouth out with soap and water...
Dart or sidebody is not just a matter of style, but also one of necessity, or at least it should be. Some figures can have an extended front dart (or a fish shaped one, which, following the same logic, is also outdated), others a sidebody, and I'm with jukes on that one, the decision should be (ideally) left to the tailor/ cutter.
But unfortunately, since the advent of the iGents, the decisions are made by the customers. So a Neapolitan jacket without an extended front dart is a no-no on certain fora. Also, not having a manica camicia will raise some eyebrows. If both are missing it's almost a waste of money.
Interestingly, when browsing through my set of 1972 Rundschau magazines, I find several examples of coat patterns (mostly DB, but always with a patch pocket) with an extended front dart.
Comparing pictures of coats with and without an extended front dart one might add to the pros of the extended version that it can support the impression of a masculine shape by visually slimming the front. Well, given that the coat is not extremely tapered in the waist in the first place.