Alcohol is used as a preservative, this being a distillate it should not be surprising that it is still 'fit for consumption'. Given that people will drink window cleaner and glycol it should be even less of a surprise but I figure the article meant that his was originally intended for consumption rather than as a cleaning product.
Poland has a fairly active bootlegging industry, and a typical reward for some favour or other is a small bottle of the local poison. Those bottles can be quite old as well and I've yet to hear of someone complaining their vodka had gone bad.
The risk is in distillation process. Even small amounts[1] methanol can be devastating.
Other than that unopened high spirits don't change much at all.
Even so, the risk of deadly or injurious methanol levels in typical distilling is low.
It's only when people are using improvisational pieces in the process (like the radiator/moonshine legacy) that things get dangerous.
In other words, making liquor (or even lower-ABV alcohol like beer and wine) is pretty safe across the board assuming you aren't just using old car pieces or old wood in the process.
I'd think that in most cases there'd be some degradation of the ABV over a long period of time that might make it susceptible to human pathogens, but that level is pretty low, something like .8% ABV.
Poland has a fairly active bootlegging industry, and a typical reward for some favour or other is a small bottle of the local poison. Those bottles can be quite old as well and I've yet to hear of someone complaining their vodka had gone bad.