I think more often than not, the problem with AF especially with the OVF in the Fuji's is one is not sure if it locked on properly until you look at the image, the rangefinder spot on the other hand gives you the idea that it was right on, still can miss but the miss could be closer. I have very little problems getting either my XPro1 or X100 to hook up when I am using the corrected AF setting. Also are you using the latest firmware AF speed especially up close has improved.
Try picking up a vintage Leica M 2,3 or 4 and see how quick and accurate your results are, there is certainly no better rangefinders than them. I think you will be surprised. I grew up using manual focus SLRs and even at my advanced years they feel more natural to use to me. Every time I use a true rangefinder it takes awhile to get the hang of focus, recompose shoot. Two avoid one of those steps, is why most rangefinder street shooters focus by zone, if you set the X100 to manual you can do that too
Secondly like I said before talk on these forums does not make for a large market to sell cameras to. Many manufactures have made modern film rangefinders like your example of the Fuji 670, or the Fuji 690s, some even with interchangeable lenses like the Mamiya 6 and 7, they just did not sell. Most love them until they forget about the parallax issues or become frustrated with the viewfinder with longer lenses or having to use an external viewfinder for wide lenses. They are niche cameras, with a small audience, compare the number of Mamiya RZs sold to the Mamiya 6s. Versatility usually wins out in the end even if people do use all that the system slrs provide. They might not do bird photos, but they like now they can.
The Fuji rangefinders were made to be modern cameras that bring up some hints of the past, I like the body form but yes they are not true rangefinders.
Lastly I am driving a manual shifting performance car again, for many it makes them feel more connected to the driving experience, but in all honesty my last car had a DSG transmission and I miss it and my next will have DSG again. The DSG is faster, one still has to shift but with an auto clutch you can be smoother and concentrate on the rest of the car's controls, I bring this up because for me, AF accomplishes the same thing, the manual art of focusing does not help me to slow down or think more or be more creative or even shoot less to make a better image, all manual focus is for me is an extra step in the way of shooting. To each his own.