The Cangany book has another couple of inaccuracies about Camco. I suspect it was the brand he had the least hands on experience with.
The Rogers throws on the snares were simply because the hole pattern is exactly the same (or so close as to make no real difference) and the Rogers were a bit more reliable. The Camco strainers tended to spontaneously throw off if you did a rim-shot. There's a couple of modifications you can do to stop it but I guess a lot of people just didn't bother.