If my memory is right, Rollei TLR is the first camera using square format. It's probably a result of the difficulty to rotate, ... hence make it square so that you can crop it to portraiture or landscape.
But then many found the beauty of the square format itself. I'm one of them. This is perhaps purely subjective. But once tuned into square format, it's hard to pull out.
So, many that addicted to the square format constantly come to yell for the square format digital camera, native square format, not cropped.
There were much hope for that, since the 35mm format and the derived are limited by the flange distance, which was targetting for 24mm in the short side. But now, the mirrorless camera does shed some light to it.