The Sony proprietary lens mount is just an updated version of the Minolta system they now own. Sony bought the SLR division of Konica Minolta in 2006, and thus gained the basis for their Alpha series of cameras. (Ref: https://en.wikipedia.org/wiki/Konica_Minolta ) Before that, Sony was already making point-n-shoot cameras. If you want to shoot low-light 4K video, the newer Sony Alpha cameras are really amazing. But, you're correct in saying that there are not as many system, or 3rd party, lenses available for the Sony cameras.