I see this "logic" on FB often, even about vaccines as I noted. I have some ardent Trump supporters on FB who were claiming Trump basically did the vaccine on his own.
Now, those same folks claim they will not take the vaccine. Just back in November they were hailing it as a masterful piece of Presidenting.
I suppose humans are for some reason highly inclined to confirmation bias and political bias. We actually had training on examples of the former resulting in bad outcomes.
Now, one can logically opine that a wall is not worth the money, fine, but to claim no wall ever in human history was a deterrent is blatantly absurd.