Are all graphic designers good in photography?

Not really some might have knowledge in photography but without the knowledge of photography one can still be a graphic designer

You can be a professional graphic designer and not have photography skills at all. These areas is to different areas you may be a proffesional in photography but not good skills in graphic design.In my opinion these are not many who is professioal in both areas.

Not necessary, but its a plus

Not necessarily. But it can be an advantage as you will be able to manipulate your project the way you want it.

that accept the look illustrated  the photographer 

Not all graphic designers can shoot the best photographs, a smart photographer is the main need for a Graphic designer.

no its not necessary, they are designers but photographer capture the nature and true pics, 

photography means capture the real, true, actual things, nature. 

Not all graghic designers ar photographers

NOT NECESSARLY , BUT I'M VERY GOOD IN PHOTOGRAPHY 

Not necessary, but in my opinion they should be. Photography helps designers to polish their compositional skills, using a negative space or creating a dramatic effect using light help designers to create designs with better aesthetic values.

Not Compulsory, if they have this skill its an advantage.