Does anybody know the name of the perspective most people paint in?
You are assuming that most paintings use this certain perspective, which is not the case. A subset of paintings do and those are landscape paintings which all of your examples consist of. This style typically uses two point perspective with the horizon parallel to the top and bottom of the frame. This could be considered landscape perspective. 

The common sense explanation is that this is how we normally see the world, and many artists are simply seeking to capture what they see, especially naive and/or traditional landscape painters as in the pictures above. Plus by selecting a specific genre of painting they by definition have the same perspective.

However there are plenty of examples of "landscape" paintings that do not limit themselves to that POV, including landscapes painted from the birds-eye POV as in the last image. I would say in this day and age, with abstract, pop-art, cubism, and all the other genres there are probably as many if not more paintings that do not use traditional landscape perspective than those that do.