I think you're absolutely right, Frank. These older designs have their own imaging qualities, which are to be appreciated in their own right but are not necessarily what the public is looking for in "the latest & the greatest."
Rollei produced various models of the Rollei 35 over a 15 year period from 1967-82. Over an even longer period, they repeatedly released commemorative versions of the model with the 40 Sonnar lens. Released primarily for the Japanese market, the Rollei 35 RF was virtually another in this line of commemorative releases, this time featuring the 40 Sonnar as an interchangeable lens. There was essentially no effective marketing/pricing strategy elsewhere around the globe. And there is no larger rangefinder product line within Rollei for it to find a niche.
It is interesting to see how other companies have also produced older lens designs for specific niche purposes. Nikon released a Tessar 45/2.8 with the introduction of the FM3A a few years ago. Because of the simplicity of its 4 element design, it is a compact lens to begin with. Nikon shortened it from 50 mm to 45 to make it even more compact & produced it as a pancake to accentuate the appeal of the FM3A, the most recent in the FM series of Nikon's compact cameras - originally developed as an alternative for the popular market to the bulkier F2 professional model of the time. Nikon's customers greeted the 45/2.8P with the same comments as RF users had for the 40/2.8 Sonnar: "Why would I pay that much money for a lens that slow?" The 45/2.8P is 3 times the cost of Nikon's standard 50/1.8 & the same price as the ultra-fast 50/1.4!
The Leica line-up includes the 50/2.8 Elmar-M - also essentially a Tessar design. Revived in 1994 as a commemorative with the M6J after being out of production for over 20 years, it has found its place as the move to higher & higher speeds mean that Leica is no longer a "pocketable" camera. However, with the 50 Elmar, it is. Leica achieved compactness in a different way than Nikon; retro on a Leica is not a pancake but is a collapsible lens. Although less expensive than any other Leica, at $750 it is not cheap.
Cosina themselves went retro with their commemorative Limited Edition release of the collapsible 50/3.5 Heliar on the Bessa T 101, available as a combined set only. Compact & retro, it too sells for a premium price at twice the cost of a regular Bessa T & faster 50/2.5 standard lens.
Cheers . . .