PlayStation one could draw between 90 and 360k polygons per second with PS4 we don't even really care to track it's drawing performance because the geometry isn't the issue. At this stage drawing triangles is far in diminished returns territory.First steps in hardware tend to be dead-ends. XB360 had hardware tessellation - silicon that went to waste. PSP had hardware bezier support - used for squat. These RT cards will be used in offline raytracing and professional imaging. Applications will be optimised for performance, and nVidia will invest in making them faster and better. Pixar will release papers on best-case rendering techniques. Etc. So raytracing doesn't need gaming's involvement this early on to progress it. Putting it out there for game developers to dabble with while greatly limiting long-term performance is a very questionable choice. A console with a limited die budget has to allocate it to where it'll get the best returns. If raytracing at a useful rate requires 100 mm² of die out of 350 total budget for GPU and CPU, it's too expensive and we can live without. If RT can be achieved with only 20 mm² of that budget, it's worth doing.
Ultimately, it's about looking at the economy and not just blindly chasing a future. The future will happen, but it cannot be made to happen any early than technologically possible. Console's can't look to implement RT hardware until that can be done meaningfully in budget.
We're going to see significant improvement in RT from this early hardware to second and really third generation consumer hardware.