Wendy's did a ghost pepper cheese fry thing some time ago and it was honestly really respectable in terms of spice, It came out during my "3 million scoville hot sauce" phase and I loved it.
Generally when Wendy's has done something spicy it's been spicy.
Most chains, especially if there large ones, and fast food in particular have business models designed to appeal to the greatest number. Often this is with a relatively small menu.
Tastes will vary greatly by area and person so “spicy” means spicy by the standards of the least spice inclined of the target demo.
The other thing to keep in mind is are they cooking it, or just heating it up? Restaurants where they cook you food rather than just heating up a prepackaged item will have more control over seasoning/flavor.
"To make poop turn that color green, it would require far more dye than is in the typical type of A.1.," said Pamela Reilly of Indianapolis, a naturopathic doctor and certified nutrition counselor
So... not a real doctor? Why would they contact a pseudoscience practitioner for expertise on food dyes?