Well, there's a quote attributed to Confucius that fits:
“When the wise man points at the Moon, the idiot looks at the finger.”
“When the wise man points at the Moon, the idiot looks at the finger.”
I saw the parent completely sidestep the content of the grandparent's argument and focus on trivial form issues, and I found this in bad taste (and an all too common occurrence), and wrote so. Simple as that. And while the quote might imply the parent is an idiot, it was simply meant as a quote that fits the practice -- as asked by Teever.