Having worked in a couple of newsrooms I have some experience with this phenomenon. To wit:
o Reporters come out of college with a BA in journalism, communications, or literature and usually have little to no background in the physical sciences.
o Assignment editors running the news desk tend to have a rather low opinion of their viewers, based on viewership ratings and their own prejudices.
o Most newsroom managers handle the "big picture" decisions and leave the copy writing to the reporters and editors.
o Most copy editors, research staff and proofreaders simply check the facts within the story and the grammar, leaving the content to the writer.
The majority of writers are either predisposed to dumb down their reporting due to their lack of expertise in the subject or the pressures of 1) lack of time for researching, and/or 2) column space and time limitations describing the subject. Over time they also are conditioned to self-edit their works by their assignment editors or others who review their work and edit out the "technical parts" for brevity and to keep the readers/listeners/viewers from "tuning out."