Does wine go bad or just taste bad?
Dos wine can go bad? It can't have mold (because alcohol), it's shouldn't have any EXTRA bacteria (because of alcohol).
In fact - the bacteria that turn vine into vinegar is acetobacter. So spotting that one in the brew is pretty easy. You start to have acid. 

Wine (depending on type of course) is pretty safe to store for a long time. That's the added value to it. You store wine  for 200 years and cash a fat check afterwards. 
The "best before after opening and store in fridge" date is usually there for two reasons:


The cork is not real one. And the alcohol will start to reacts with it. 
The wine was made in such manner that the yeast didn't die (so not enough alcohol content and with that extra air after opening they will start to digest carbs again). 


What can change the taste of wine is storage type. Like in the answer you provided. Bad storage will lead to bad wine. Or not bad WINE but some bad liquid.