Scott, I wondered about that, too. The photos of cars with handrails in the Narrow Gauge Pictorial were all taken on the southern end of the D&RGW lines. But then, they were all taken when the southern end was about all that was left of the narrow gauge, so there wasn't a clear causality. But it sure makes sense to me.
I had planned on adding in some freight cars to my passenger consists. I guess I'll have to put a handrail on top of the front-end cars, then.