A meaningless blanket statement.
Methanol is a poison, far worse than ethanol, yet you've likely consumed it in small quantities from what you would think of as non-alcoholic sources. If there's no safe level alcohol consumption, you'd best stick to consuming your fruit unripened or avoiding them entirely. Again, relative toxicity is meaningless without also taking dose into account.
You could easily say the "correct" amount of oxygen is toxic, much more so than nitrogen even at sea level, and not be technically wrong. Change up the pressure and mixture and you might find the nitrogen causing more immediate (though not toxic) danger.
For me the "poison" is a substance that when ingested has a significant detrimental effect on one's health. Until recently there was a myth that moderate consumption is harmless, or even beneficial. The research like this show that even small dosages have negative effects. Moderate drinking might not kill you immediately, but still it is healthier choice to avoid alcohol completely.
In the human body cells which are not performing their correct behavior kill themselves. Otherwise they can become cancers.
"Well you see, Norm, it's like this... A herd of buffalo can only move as fast as the slowest buffalo and when the herd is hunted, it is the slowest and weakest ones at the back that are killed first. This natural selection is good for the herd as a whole, because the general speed and health of the whole group keeps improving by the regular killing of the weakest members. In much the same way, the human brain can only operate as fast as the slowest brain cells. Now, as we know, excessive drinking of alcohol kills brain cells. But naturally, it attacks the slowest and weakest brain cells first. In this way, regular consumption of beer eliminates the weaker brain cells, making the brain a faster and more efficient machine. And that, Norm, is why you always feel smarter after a few beers."