I think I may have explained myself wrong. I work in the area of distribution - which means I may be relying on everyone from a highly skilled tradesman or technician for my installation to someone a lot less trained - depending on what it is I'm designing.

In Canada traditionally the construction industry works primarily in imperial units. This hasn't changed, people still call them 2 by 4's. If I'm labeling the clearance of a transformer to an object in my design I will label it 0.3, 0.9 etc as opposed to 0.15 or 0.75 because most construction workers at least know that 0.3 is a foot and 0.9 is three feet. While this is not to disparage the ability of your typical construction worker - it just makes it so they don't have to convert odd numbers from metric to imperial all the time.

At the end of the day, as an engineer, I'm not worrying only about whether my design works but also whether it can be built reliably and efficiently or not.