Poor Drafting Practices
And while we're on the subject of scaling CAD drawings - I use lots of downloaded CAD files from various manufacturers' websites (cylinders, bearings, widgets, etc.).
BEWARE of drawings from McMaster-Carr! Most of their drawings I have downloaded are drawn scaled!! Not full size! A 6" dimension might actually measure 3" on your screen. The drawings come with a border intended for plotting on some certain sheet size (like that has any value to a customer). I'm not going to plot it. I'm going to insert it in my drawing.
Apparently the CAD contractor they have hired to make their drawings is violating RULE #1 of CAD - NEVER scale the drawing to fit the plot! Scale the plot to fit the paper. They seem unaware that one of the main purposes of downloading CAD files is so that the parts can be inserted accurately into a larger assembly or arrangement. If a bearing you are expecting to come in for a 2" shaft shows up on your screen at half that size, you think you have downloaded the wrong file. Also, if you need to modify any of their drawings, the reduced scale can really screw you up bad.
For what its worth.