The negative examples are different because they don't suggest an argument, only a counterargument. If X is an apple then various conclusions (typically/intuitively) follow, for instance, that X is edible. But if X is a non-apple then nothing much follows from that; it only serves to block the apple-->edible argument (and suggest that X is not necessarily edible).

"Money is speech" implies that all of the protections that get applied to speech should be applied to spending. If money is not speech, then who knows? Nothing much follows directly from that (it's not as if there's some general principle that things which are non-speech should be banned); it just suggests that we don't necessarily have to apply the speech protections to spending. It's more similar to the "MLK was not a criminal" counterargument than to the "MLK was a criminal" argument (note that being a non-criminal doesn't make someone especially admirable), but it doesn't fall into the trap of being obviously false.