I agree that when men dye their hair it often looks less 'real' than when women do it. Maybe because men just don't read directions? : )
Yes, the double standard is irksome. It's why you rarely hear a man say "I look older with grey hair" but you hear many women say just that.
It's an illogical statement no matter who says it tho. Dying your hair doesn't make you look younger. It makes your hair look younger. Dyed hair doesn't take away wrinkles or age spots or saggy bits. It doesn't make your heart or lungs or thyroid younger. But, if it makes a person feel happy to dye their hair, men or women, great. I'm one of the champions of people doing what makes them happy.