Another thought that just occurred to me on this topic can best be summed up by "Location, Location, Location". Where you live might be (and most likely is) a factor in how your pool is constructed. I happen to live in Florida on a a 2 block wide barrier island between the Atlantic and the Intercoastal Waterway and salt spray is everywhere. We just accept it as a fact of life--one of the prices you pay for living by the ocean. Therefore, materials used in all construction tend to be possibly a bit more salt resistant than materials that might be used elsewhere. (This thought occurred to me as I was rinsing the salt off my car!) This goes along with what Chemgeek said about water quality in Australia and the material they use there as a result.
Perhaps a better title for this thread might be "Is your pool constructed of corrosion resistant material?" intstead of "Downsides to salt pools".