Because I'm a structural engineer, I like to think about the future of structures, not bicycles. Many good ideas came about by taking something from one obvious application and transferring it to another. I also don't think we will be using reinforced concrete in the year 2070 the same way or as extensively as we are now - the carbon footprint is too large. Maybe these new materials can spawn completely new types of structural systems that were never possible with conventional strengths and stiffness. Low weight is ultimately a goal of structural engineering as well, but not to the same extreme as sporting goods. Obviously cost comes into play, but many things that were once prohibitively expensive are now used on structures, including carbon fiber.

Elasticity (or in the case of conventional materials, ductility) is a trait that has applications in seismic design, so I disagree with your last claim. The trick is combining the good parts of that material with the good traits of other materials into a composite that achieves stability under gravity and predictable deformability under seismic loads.