Its RPG not a shooter. Nobody forcing a sword on to your head and force it to use it. If you don't want to use dragon shouts don't.
I don't know I going to use it or not. Time will tell.
Is it really that important?
That gameplay footage we seen in February and those demo we seen so far its only a tip of a very large iceberg.
How do we know in the game there is something really cool that we have not seen yet.
An angry dragon may force a player to fight it or die. And after being forced to kill a dragon you get forced to shout out DOVAHKIIN!
You can't really expect people to manage to avoid dragons forever.
Edit: Assuming that the shout happens automatically after defeating a dragon of course.