I thought the same for some length of time, and am (or was) a big Leica rangefinder snob but having used a mates R6.2 and rented an R8 on a few occasions I was most impressed and depending on the job they are fine quality camera’s in their own right. Rangefinder’s have their limitations and aren’t suited to many situations, especially with regard to long focal lengths and of course macro (or correctly micro) work.
The optics for the reflex series camera’s by Leica are still top notch. Glass is what counts, that captures light … the rest is just a box holding the film whilst it’s wound.
//still gotz my M6 … ashamed to say I probably haven’t put a roll of film through it in 4 or 5 years.