I guess I've been lucky (or was it my customers?
) over the years as the very few times that this was really an issue (as compared to most failures being totally dead output) rebuilding the alternator or replacing the regulator has been the cure. I see what you're saying and agree, I just think it's less likely to occur, based on my experience, for whatever that's worth. Usually I find that if nobody has monkeyed with the wiring you can pretty much count on it being o.k., 90% or more of the time.
BTW, while the bees are buzzing around nearby...
I happened to notice under the hood of a 2001 Ford Taurus today (who knows what they're called in other markets) the alternator output wire is approx. 6 ga. wire. I suppose they grew weary of poor connectors and insufficient wiring causing underhood fires.