Very clever, but missing the point. Those two qualifiers refer to different classes: (1) Most startup theory is ex-post, therefore bs. (2) All ex-post startup

Very clever, but missing the point. Those two qualifiers refer to different classes: (1) Most startup theory is ex-post, therefore bs. (2) All ex-post startup theory is bullshit. Those claims may or may not be true, but there's no contradiction between the two. The title does indeed seem to implicitly claim (2), in the form of the following (implied) syllogism: Most startup theory is ex-post. All ex-post startup theory is bullshit. Therefore, most startup theory is bullshit. Or, more concisely: most startup theory is ex-post, therefore bs.