That's true -- in the regular consumer world, castile is basically an all-veg oil soap and that's the way Kirks and Bronners use the word to sell their soaps. In fact there was a 1932 legal battle in the US that gave credence to this meaning of the word out in the real world.
But in the soaping world, at least what I've seen of it, castile usually carries its original more-specific meaning of a 100% olive oil soap. I can accept both meanings of castile, but each in its own respective context.
Maybe Lee, who is perhaps a newish soaper, is using the word more generically to mean an all veg oil soap, but when I say castile in the context of talking about handcrafted soap, I mean very specifically a 100% olive oil soap and I think most other soapers I can think of will tend to do likewise.
It's kind of like "assault and battery" -- the term means something very specific to a lawyer and means something related but much less precise to everyone else.