Well, taken in the context of ease and accuracy of composition and focus, it is not easy for me to use the wlf by holding the camera upside down and at arms length! For subjects like landscapes over brush and pointing down at things on the ground it adds complexity.
ps I suspect people have different perspective because of the subjects we shoot. I shoot primarily landscapes, where a foot or so higher viewpoint makes a big difference in perspective, and where precise leveling and framing are needed. I also shoot a lot of graveyards and stuff washed up on the beach, where pointing straight down is common. I have never been in a situation where I wanted to shoot over a crowd or straight down the face of a building. I sometimes also have glare on the screen from bright overhead sun.