Good point, many people (and books) will not take different climates into account. We have an excellent bridge builder in Arizona, but he insists on using raw steel, and will powder coat if asked.
In arizona, it is so arid, that bare steel will get a thin coating of rust and then it will sort of self limit.
Elsewhere unpainted steel will dissolve. Near the coast (where I live), a small amount of salt air will get through a scratch in powder coating and form a blister, actually trapping moisture to hasten the rusting process.
Could never convince this guy to make some stuff in aluminum or stainless.
Likewise some climates, track power with brass is very simple, low maintenance, others have so much pollution or other things in the air, it's impossible.
But you get "books" from "experts" where there is only one way to do things, and of course it does not work for everyone.
Greg