Considering that much of society seems to be mistaking the bath water for the baby it might not be too bad of an analogy.
However, using that particular analogy in an argument is problematic. You couldn't argue in support of Illich because then you would be in favor of throwing out babies. It provokes a specific emotional response and inhibits critical thinking.
Sent me rushing to my little blue, although now much coffee stained, "Miniature Guide to Critical Thinking Concepts and Tools." and on to the Wikipedia entry on logical fallacies.
Maybe drawing from a less emotional analogy would be helpful to assess what Illich was saying.
How does the Zen saying go? Don't mistake the finger pointing at the moon for the moon.
Illich was talking about looking away from the pointing finger and looking at the moon directly. Once you have the moon in view, there is no need to keep looking at the finger.
In the case of learning, once I know how to learn there is no need to keep concentrating on the "forms of education" that taught me how to learn.
hmmm...I'll keep noodling at this.