That would be because most SLR prime lenses are a retro-focus design that is based on a double-gauss formular (these days). Boring and rendering mostly the same way. Rangefinder lenses tended to use different formulas to acheive different effects, even at the same focal length. A Sonnar 50mm certainly renders a scene differently than a 50mm Tessar, Gauss, or other design. As to why they were called what they were called - who knows? I imagine they were named by their (the lens formula) inventors, and in cases where a copy of an existing design was made, by the company policy - giving us Heliars and Ektars and so on.
But I'm just guessing based on what little I know. Maybe there was some deeply involved logic in all of this. I agree though, it is very interesting.
If you find yourself fascinated enough, peruse eBoy for a used book on optical design. You can see the design evolutions from Rapid Rectilnears to Petvals to Triplets to Tessars and so on - appeals to my geeky side. And then trying out a lens made to that specification can be lots of fun too. Something you can't generally do with an SLR that easily. Well, you can with an adapter. I do that, too.
Immanentizing the eschaton since 1987.