I've been watching a few of my Blu-ray collection lately and was wondering why all of them are in 16:9 widescreen format

. I'm a bit cheesed off i mean I have a large TV and i want it fully filled with HD Films not cut off and widened.
Anyone agree or know why film companys do this ?
I want more films to fill my whole screen. The only one i have watched with full screen was a No Country for Old Men Trailer. Looked awesome