Yes, fifty years ago I used a rangefinder, but when I got a Pentax SLR I thought I had died and gone to heaven as far as ability to compose.
Yes, I closed one eye. I was interested in candid shots so I had to be very fast, too fast for me to use a rangefinder, especially when the subject did not lend itself to easily seeing when the split image became one image. I would see a possible shot, bring the camera to my eye very rapidly, take the shot and put the camera down. I did not want to attract the attention of the subject. This method of shooting required me to preset the focus and rely on a smaller lens opening for a reasonable depth of field. Hence, I had to forget about completely blurring the background, easy to do with the Nikon set with a large lens opening.

I do not see how a zoom lens "defeats the genre" of street photography unless one is fanatically devoted to the notion that the only good street photographs are made closeup and with a 35 or 28 mm lens.

I am not troubled by the fact that Leica has its devotees. My review presented my personal feelings about using a rangefinder camera lacking autofocus and zoom lenses for candid street photography.