> That said, if it's such a catastrophically stupid idea, I'm not really sure why it had to be shot down so harshly

To avoid the catastrophy that makes it a catastrophically bad idea.

> I assume the real reason it was shot down was out of fear that it would work well. Does anyone else have a better explanation for why there was such a visceral response?

It had already worked badly (subpoenaeing the key adverse witness, who would provide a basically automatic defense win, and one of the most common wins for this kind of case, if they failed to show up.)