What's so hard about "prosopagnosia"?

You may well disagree with me on this -- my friend Betsy already has, strenuously -- but I thought it was odd of the Times Book Review to make such a fuss over prosopagnosia, the medical term for face blindness.

In yesterday's review of  Heather Sellers's new memoir, Mary Roach told readers that

"You Don’t Look Like Anyone I Know" does not read like any memoir you know, largely because of a condition you may not know and certainly can’t say: prosopagnosia.

Now, I don't object to seeing a rough pronunciation key supplied, as Roach does a bit later: "It's  pro-so-pag-NO-see-uh," she confides. But is this really a difficult word? Yes, it's long, and I can imagine a momentary pause while the reader considers whether this is the -gn- of  lagniappe or the -gn- of agnostic. But I don't see anything else that's likely to slow down the typical Times reader.

Hyperbole like "a condition you ... certainly can't say" is generally frowned on in journalism, because -- like the classic bad example, "For anyone who's been living in a cave" -- it risks insulting readers. But I'm not a hard-liner; I think plenty of English words are tough to sound out, and plenty of others (like Zagat, which also rated a Times gloss yesterday) are hard to remember. I just don't see how you'd take prosopagnosia to be one of them.