I can, in that given situation. Your assumption is that John Smith should be told "you screwed up" for dropping the prod tables. He shouldn't - he made a normal mistake. The negligent party here, who should hear the words "you screwed up," is Johnny's boss or tech lead, who decided that those tables should be droppable in the first place, despite the obvious risk.

"Negligent" doesn't just mean "made a mistake." It means something more like "their carelessness led to a mistake."

That person hearing "you screwed up" will cause significant behavior change. I daresay it will encourage them to make the prod tables very hard to drop, and since they are presumably a smart person, when combined with the postmortem of the incident, it will encourage them to look for and proactively fix similar problems, and generally align the team with good DevOps practices.

It is important in all of this that the right person gets the message. I assume you expect that to not happen, since that is one of the theses of "blameless postmortems."