Some do. Mitch Alland comes to mind. He's been using Ricoh GRD cameras for a long time; see
this thread and scroll down to "LCD versus viewfinder" for his take on it.
Hej, Anders!
The key aspect for me of using the LCD is, as I wrote in the thread you linked:
Indeed, I have Zeiss 28mm and 21mm optical finders that probably are the best ones around and don't use them with the GRD3 because, for street photography, I prefer the "looser" and more fluid style that using the LCD encourages: what I do is to establish the edges of the frame by looking at the LCD and then look directly at the subject when pressing the shutter.
Another advantage for street photography is that subjects often are not aware whether you're taking a picture or simply looking at the LCD. Many people like the "directness" of a viewfinder in a rangefinder camera, but looking directly at the subject, once having framed roughly with the LCD, in my feeling, is still more direct. I understand that many prefer using a viewfinder. All I can say is that this way of shooting transformed my street photography when, four years ago, I shifted from using the M6 to small-sensor cameras without viewfinders.
I should also state that framing with the excellent high resolution LCDs, that can be used even in bright sunlight, on cameras like the Ricoh GRD3 and the GXR/A13 allows, with experience, to judge exposure without having to look at the histogram. For this purpose I use manual (spot) exposure on these cameras, which on the latter cameras is implemented well: you press a button to "center the needle" to the the recommended exposure and then move the ADJ lever on the back of the camera to the left or right to decrease or increase the shutter speed until you have the look, that is, the exposure, that you want.
As for the X100 hybrid viewfinder, if well implemented, it could be a great step forward. If I had the X100, I might use it occasionaly particularly because of all the exposure data can be shown, but, for me, it would be a trade-off with the size of the camera — I might one that would be smaller than the X100, like the GXR with the forthcoming 28mm-e lens/sensor module. Also, I might miss judging the actual look of the exposure unless that would be visible as accurately as on the LCD by swtching to the EVF view.
I think that people who simply assume that framing with a viewfinder is better and, and don't try seriously to frame with the LCD are missing something.
—Mitch/Bangkok
Bangkok Hysteria Book Project