Walnut Creek Nordstrom Ramp Too Steep for Wheelchairs

This ramp is located by the Walnut Creek Nordstrom men’s department; the main ramp is wheelchair accessible. I wonder what the story behind this is. It’s obviously designed to be wheelchair accessible, so were the laws changed about maximum slope, was there an accident that caused them to embed that sign into the ground, or was it something else? Does anyone know what happened?

Also, note the spelling, “WHEEL CHAIRS” as opposed to “WHEELCHAIRS”.