Engber considers the prevalence of "cat hoarders" (who are usually women) without considering the most obvious -- at least to my intuition -- cause: toxoplasmosis infection.

Toxoplasmosis is a disease caused by a protozoa parasite whose lifecycle can cross cats and other animals, but only sexually reproduces inside cats. There's strong evidence that toxo-infected rats and mice have their behavior affected by the parasite in ways that make them more likely to be captured by cats: their reactions are slower, they're less fearful of new situations, and they even seem to be drawn to the smell of cat urine (whereas non-infected cat prey will wisely avoid all cat smells).

There's also evidence toxo-infection can have analogous effects on infected humans -- subtly altering their personality and making them more prone to, among other things, dangerous accidents. This writeup (which I believe is an uncreditted reprint of a New Scientist article) is a good summary. Let's compare Engber's observations about "cat ladies" with the observed effects of toxoplasmosis on mammals:

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