Your point is true. However, I've found in real world use that we don't go through the low-res "wireframe" much anymore. We skip right to the meat of things

Your point is true. However, I've found in real world use that we don't go through the low-res "wireframe" much anymore. We skip right to the meat of things since working in Keynote is just as quick. I'll also add that it probably matters if the consumers of the mockup/prototype/wireframe/whatever are internal/external to the organization.