The drawing isn't the document; it's a part of the document, like Chapter XIV in Moby Dick. Maybe the difference is largely nomenclature, in that you're viewing the drawing as a product, analogously to a computer program, where I don't: it's a step, used to describe a part's geometry and no more a complete part description than "steel." On a drawing, one wouldn't say "bolt" without quite a lot of further information, like the size.
From here on was added in an update.
Oddly, I agree with many of your issues with LP, in that it adds a pre-processing layer, and even adds the complication of re-ordering code. I tend to view it as a very elaborate scheme of commentary, which may be a complete misinterpretation of its goals.
Information about American English usage here and here. Floating point issues? Please read this before posting. — emc