It’s a self-reinforcing cycle. If you write directions at too high a level, people don’t read them and call support instead so someone can explain the directions with more and smaller words. So if you’re writing the directions and taking support calls, you have an incentive to try to write your directions at a low reading level to reduce your future support burden. (That doesn’t make you any good at it.) Which, if your hypothesis is correct, hurts the readers’ ability to read complex sentences a little bit in exchange for reducing your support burden by a lot.
You’ve just described the entire language of Toki Pona. The same string of words can mean “bear” or “elephant”, and I copied a phrase someone used to mean “tiger trap” and it was read as “bamboo arch”.