“But I never quite understood why people like rangefinders more?”
Some people prefer rangefinders because they do not black out during exposure with a mirror flip. With an SLR or DSLR, you never see the exact moment the shot is taken because the mirror flips up to make way for the light path.
Rangefinders are also much quieter than SLR’s because they don’t have the mirror mechanics flapping.
Rangefinders are also much less susceptible to micro vibrations during exposure, again because of the lacking mirror box flapping.
Some people like rangefinders because the cameras and lenses are typically much smaller than SLR designs.
Some people like rangefinders because the traditional quality Leica’s and Contax cameras accept Leica and Carl Zeiss lenses, considered by most to be the best in the world.
The allure of rangefinders is only valid for the quality versions. Not applicable to the point and shoot cameras with noisy auto wind.
Leica rangefinders earned their reputation in war time photography. They barely make a “tick” when taking the photo. The SLR design is loud comparatively, and thus more likely to get a photographer shot dead by an enemy who doesn’t like having his photo taken without permission.