Older movies shot at a lower frame rate do look like they were shot on video when those sports/game modes are engaged though. Some people may think it's cool, but it's not what most movies are supposed to look like.
Many HD sets have the thing on by default out of the box, and the off switch is usually buried deep in a sub menu. Check out most home theater setups at stores like Best Buy and the "soap opera" effect will be noticeable.