But Jesus drank wine, so why no alcohol?
Well, again, as I recall the original Greek was "fruit of the vine," as far as communion goes, but the first miracle (water --> wine at the wedding) was most distinctly wine.
And I have actually heard some legitimate arguments for not drinking alcohol at all without actually saying that alcohol is inherently bad. Being that while it's not inherently bad, it's better to not even put yourself in the situation where you would potentially cross the line of moderation, intentionally or not.
That said, I actually like wine. And yes, I only drink it when it's legal, thank-you-very-much. (Ie, when I'm in Canada or Britain with a lower drinking age, or at Communion....)