You can't seriously be trying to tell us that all factories produce perfect and accurate threads and that all their cutters are sharpened to perfection and excellent and are consistent from factory to factory and country to country ...hehehe...be real.
I'm not. Those are your words.
However, being 'real' for a moment.
On the subject of problematic threads I think that the Indifferent Crucian makes a good point. On the MC reel one shouldn't be using adhesives to secure threads - I don't on mine.
I'm saying that machines will make threads more consistently than by hand. Machines need setting and from time to time the tooling will require changing - but machines 'do' repetition. (being 'real')
Even those really expensive Centre pins (mentioned many posts ago) feature components that are made on a lathe (again being 'real' - a machine)
Mark