A couple of reasons why not.
First is the focus problem. A longer lens has shorter DOF in general, so you either have to make the long lenses very slow, or you have to have a wider rangefinder base (and thus a larger camera body) to focus more precisely. This is also part of the reason why MF rangefinder lenses aren't particuarly fast. The other part of the reason for that is that the lenses have to cover a larger format and would need to be inconveniently large to get an aperture like f:1.4.
The other is the viewfinder problem. A wider focal length range requires a more complicated viewfinder, either with more framelines or with a more complex zoom arrangement. With very wide lenses you can use an auxiliary finder mounted on the accessory shoe, but wide lenses have wider DOF and don't require precise focusing.
Leica made it possible to use long lenses on Leica rangefinders with the Visoflex system. This inserted a periscope kind of thing between the lens and the camera body, so that you could actually focus through the lens as with an SLR. It was a bit of a kludge--better to use an SLR for what an SLR does well and a rangefinder for what a rangefinder does well.