I have a few bottles of very nice aged balsamic that I opened, but would tend to stick aside and save for something good that never really happened. Each of the bottles has been open 2 or 3 years, one was opened 4 years ago.
Can balsamic go bad? I know it's aged in barrels before it's bottled, but it's my understanding that is different and not the same as after it's bottled then exposed to light and air. The balsamic was aged 15-25 years before it was bottled, and was very expensive. I don't know why I never considered dining alone to be good enough to enjoy it, but there you go.
Does it degrade and spoil?