The types of arguments discussed here ("once someone predicted a bad thing and didn't happen therefore no bad things will ever happen") seem to be based on vibes more than logical statements. Twitter is rife with specious arguments that may have an appealing ring of truthiness to them but dissolve under the slightest scrutiny.

Trying to fathom what kinds of people would seriously believe that the underlying basis for the argument holds is to misunderstand the audience and their modality of reasoning.

It is indeed disappointing that most people end up with ideas and opinions that don't hold up to any kind of scrutiny but it is also the world that we live in, so we shouldn't be terribly surprised by it.