Given the widespread belief in Zapruder film fakery, it is not “self-evident” that it is nonsense.
There is a poster on the EF that pushes this using pages of mathematical calculations purporting to show the film was altered. I think he and perhaps one other person understand what he is trying to say. Most people stop asking questions about it. But if it has math, it MUST be right.
I think it is self-evident nonsense. If one dives immediately into the bewildering "evidence of alteration," which is what they want you to do because then you are playing on their turf, it can start to sound halfway plausible. If one steps back and asks, "Wait a minute, in what meta-narrative of the JFKA does this make any sense? Explain to me why they needed to do this and why they would have done it the way you say they did." - well, then it all falls apart. It's very much like - as I know from considerable experience - debating with a Flat Earther or Young Earther. As long as you stay on their turf, their "evidence" is sorta-kinda persuasive. When you step back and say "wait a minute, bub," it's complete nonsense. I had always assumed the whole Flat Earth thing was tongue-in-cheek, wink wink nudge nudge, folks just enjoying being different and having fun. Noooo, not at all. 84% of Americans believe the earth is spherical, while the rest either believe it is flat or have their doubts. Does this mean the Flat Earth is not self-evident nonsense? It is not self-evident nonsense only to the 16% whose cognitive faculties are not tracking in the channels of normality, at least on this issue and probably many others.
(Apropos of the current Ed Forum Follies, I participated on an active forum called White Horse Theology that went completely poof overnight - no warning, no explanation, just poof. Before it went poof, I was astounded at the number of participants who had intelligent things to say about philosophy and theology but who were also Flat Earthers and Fake Moon Landing-ers. They became positively irate if you dared to suggest these beliefs were just a bit irrational. And, of course, they would inevitably point to the not-insignificant number of people who believe these things.)
I sometimes sound like a John Orr groupie, which I'm not, but there is a theory that hangs together. He accounts for Oswald, he accounts for what occurred and why, he accounts for the physical evidence. It's internally consistent, even if one doesn't find it persuasive. You have to confront his evidence and arguments. You can't just say THAT MAKES NO SENSE.