>>2942166RFs remained a popular meme after the invention of the SLR not because the form of focusing is nice, but because by being necessarily coupled to such a focusing system, most rangefinder lenses have historically had more accurate focus scales than SLR lenses (where the scale is often inaccurate; think to all the off infinity marks you've seen)
That precision coupled with a short focus throw that muscle memory is why rangefinders are popular with the people they are. The majority of heavy rangefinder users do not actually use the rangefinder mechanism itself that heavily, except for fine-tuning focus when its necessary. Knowing your way around the scale is how these cameras are meant to be used.
In recent years (90s rangefinder revival and onward) it's become a meme to say you prefer the rangefinder focusing mechanism, but this is mostly gearhusbandry. The Leicafags most likely to be seen actively (and strenously) using the rangefinder mechanism are the ones that are buying it to shoot their family. Seal related.