I think it was false advertising for the manufacturers to call 1.78:1 HDTV ("16:9")
widescreen, when it was really "
narrow screen" compared to the ARs of any American theatrical aspect ratio, except the old 1.37:1 and 1.33:1. When widescreen came to the theaters in the '50s, most people reserved the term "widescreen" for ARs of 1.85:1 and larger, and my friends and I usually had even wider in mind, e.g., 2.2:1 (most 70mm), and most often 2.35:1 (now virtually replaced with 2.39:1, rounded to 2.40:1 by many writers). Leonard Maltin doesn't even include 1.85:1 in his widescreen AR list anymore, since 1.85:1 is usually as narrow as it gets nowadays (except for weird formats like IMAX, and the horrible HDTV AR).
Do we think the manufacturers of HDTVs used the ratio of 16:9 in their advertising so that the consumer wouldn't realize that it was narrower than even 1.85:1 without doing the math?
Do we think that some fine day, not too long from now, they will attempt to sell us flatscreens with ARs of 2.39:1?
I'd probably be enough of a fool to buy one, for the sake of immersion and impact, if it were not for my hope that I will have front projection with Common Height by then.
When that day comes, it will be 1.78:1 and 1.85:1 that will look weird, because they don't fill the home screen. I'm sure that filmmakers who use a lot of true widescreen take comfort in this.