True, but that doesn't mean FP is a bad idea or that they'll get rid of it because of those guests who are confused by it.
Speaking of FP, WDW could do a lot better job with signage for the entrances to their rides. I'm pretty familiar with the rides and the lines and even I have to sometimes stop and hunt around to make sure I'm getting in the right line looking for the FP entrance or making sure I'm not accidentally getting into the FP line when I don't have a FP. Sometimes I'm even taken aback by the sign "Stand-by Entrance" and my brain goes, "Wait, what is stand-by? Is that a fancy way to mean FastPass or some other elite group? Oh, it means simply, that this is the line." Who the heck thought to name "Entrance" with the insider terminology "Stand-by Entrance"?
Would love it if there were just two very easy-to-spot arches with one that says "Entrance" and the other that says "FastPass Only."