Dear Korrol,
I think you'll find that it's legislated/written in regulations that the Cabin Crew make those demonstrations.
Much like other signs, literature, etc in society, everyone has to cater to the "lowest common denominator".
As someone else mentioned, there are many people on most flights that ARE interested in where they are, how long to go, the weather etc.
You're probably that person that continues to talk on your mobile phone after doors closed, even though it's been said several times to turn it off. But I suppose YOUR call is THE most important.
The Darkness