It’s not. A couple years ago there was a group of bloggers, writers, and critics who started carrying on about “natural” wine. Of course, nobody knew what that was, so they came up with a definition of sorts. Joe Dressner had it on his website and several wine writers started to champion those principles, which among other things included using “natural” yeast, “minimal” or no sulfur, neutral oak, and non-interventionist techniques.
Putting aside the obvious point that all wine making is interventionist, from cloning, grafting, planting, trellising, green harvesting, leaf plucking, picking, sorting, crushing, fermenting, etc., it always seemed a bit weird to pick on sulfur and yeast as the big factors.
It is a rather unfair argument as well, because it’s not like there are two camps or anything - there is no camp that I know of that advocates adding truckloads of sulfur. It’s a very ill-defined line. The idea is that adding too much sulfur is artificial, adding just enough is natural, and adding none is also natural.
The amounts added tend to be very small and you can ruin a wine by adding just a small amount too much, so how can anyone decide what “minimal” is? Nobody deliberately wants to ruin their wine with too much.
In addition, not adding any at all, which in principle is perfectly OK with me and I suppose everyone, means you run the risk of your wine crapping out when you ship. So there are winemakers in say France, who may not add for the domestic market but who will add if they’re shipping. And again, it’s not like they’re adding it by the ton.
Since Roman times people burned sulfur to clean barrels because it destroys microbes. When wine was stored in those barrels and shipped, it ended up lasting better than wine sent in new barrels. Finally in something like the 1490s the Germans ruled that sulfur could be added to wine.
If you ever go to a health food store and see dried apricots that are unsulfured, they tend to be brown. The ones you buy in a supermarket tend to be nice and orange. Why? (BTW - the apricots also contain a lot more sulfur than most wine.)
The reason is that oxygen serves two functions - it is an anti-microbe, destroying stray yeast cells and bacteria, which people had figured out in ancient times even though they didn’t know about microbes, but it is also an anti-oxidant, mopping up excess oxygen in the wine and preserving it. That’s why your apricots don’t turn brown.
Occhipinti had the first problem - she had bacteria and other things that created volatile acidity in her wine. I never had any aged, but I would assume it would be oxidized.
Now pick a wine like SQN. I don’t know a damned thing about the wine making for that wine but the wine is big, ripe, sweet, high-alcohol. In fact, the low pH and ripeness are great breeding grounds for some bacteria and yeasts. With no sulfur, that wine might have problems. If you’re a wine writer who champions “natural” and you hate that SQN wine, you demonize it. You accuse the winemaker of using spinning cones, micro-oxygenation, lots of sulfur, and other “interventionist” things. Basically you dump SQN, Two Buck Chuck, Apothic, Yellow Tail, Mondavi Reserve, Chateau Lafite, and pretty much any other wine into the same bucket - “industrial”, “interventionist” or whatever. Doesn’t matter whether it’s a peasant producing a few barrels or a large corporation - if they use sulfur or “commercial” yeast, they’re not natural.
IMHO, “natural” is great but it also is an excuse for a lot of flaws. Every once in a while Bob Parker will tie one on and tweet out a rampage about such wines. Frankly that’s just as bad as demonizing anyone who dares to add some sulfur, because surely there’s an entire universe of wine between “no sulfur added” and “overwrought crap”.
So it’s not like sulfur is necessarily frowned upon by most people. My hunch is that most people would really prefer not to use it. But even more, they would prefer not to have their wines spoiled or oxidized and it turns out that a little sulfur is one of the least objectionable ways of ensuring that.
If you ever get to taste freshly-bottled wine, you’ll likely pick up some raw sulfur. It’s one of several reasons you want to let the wine sit for a bit.