I suspect that the maximally weatherproofed and sturdiest pro-grade cameras may not have the articulated screen because the designers are worried about failure under extreme conditions. My consumer grade APS-C DSLR, Canon 60D, has the articulated screen, and I love it. Admittedly, most of the time the screen is folded back into the body (screen facing out, or backing facing out), but if I need to shoot low, it's there to be deployed. I worked with a Canon Rebel T1i (no articulated screen) as a medical specimen "copy camera", backache could ensue from longer photo sessions.