WTF is Oxidation? Is it a mistake? Or is it a trend?
When you leave something exposed to the elements, chances are it will go bad.
In general, oxidation in wine is a bad thing. The overexposure to oxygen dulls the aromas and flavors of the wine. It is one of the known and recognizable "flaws" of wine, that can help you point out when a wine has not been handled or stored well enough. Oxidation could be a small, subtle flaw that is at least an inconvenience, or it could totally ruin a wine. Either way, it is impossible to reverse.
On the other hand...
Oxidation is becoming one of 2017's outlying trends. Why? Oxidation adds flavors of bruised or dried apples and nuttiness to white wines. That does not sound TOO bad right? Those flavors actually sounds fairly pleasant on the face of it, and they can be. Oxidation has been a part of the winemaking process in France and Spain for a long time. We see it sometimes in white Rioja, and in the process of making sherry. It can be a good thing.
Problem is when our tastes shift even in the slightest, some winemakers have a habit of taking those tastes to the extreme. Its like craft brewers adding EVEN MORE HOPS!!! to their already bitter IPA. Yeh, people like hoppy beers but when you overdo it the beer ends up tasting like bitter cut grass. Blech! Hops is supposed to add subtle flavors to beer, not overpower it. Same thing goes for oxidizing wine. You can add some really cool and unique flavors, when used with restraint and finesse. If you go full on oxidizing, you overpower and ruin the wine.
Basically oxidation is the sign of a wine that is on its way to being ruined, but because of what happens to the wine its not always the end of the world. Some winemakers want a little oxidation to take place, but too much will make a great wine taste flat.