Well, i'm not a movie hobbyist...
I mainly use my projector for playing with the xbox360. Okok, i watch movies with it aswell.
But i do believe that the guidelines are not for movies. They should be in general, regarding
image quality. If you are too close, the quality will become more bad (well, it stays the same, but you can see more detail the closer you are... or with other words, you can see how "bad" the image really is (not saing the image is bad, i have a HD projector :schwitz
).
However, i understand your point there. You're still sitting a bit close tho.