1) I can't tell if it's much older than others. The estimates I can gather (Wikipedia, mostly) for their length of time mostly points to “at least Neolithic”, so it's not clear if any is much older than the others. In particular, the “since Neolithic” interval is quite short in relation to human evolution. (Though I don't deny some evolution happened since then (we know some evolution happen even in centuries), it's short enough to make it unsurprising that not all its influences had time to propagate to the species.)

2) On a stronger point, alcohol was only available after the humanity evolved. Thus, as something that an addiction-protection–trait should evolve for, it hasn't had a lot of time compared to traits that protect us from addiction to everything else we consume.

Um, alcohol was the most common method of water purification in Europe for a long time, and Europeans evolved to have higher alcohol tolerances.

Not sure if this helps your point or undermines it, but it seems relevant.