People had asked for brewing in some form for some time now.
Like a long time.
Years.
Where on earth those people are now I can't even begin to guess. We have something they wanted for years and I haven't heard from them in the slightest.
You can roleplay being drunk without drinking in-game liquor, surely.
Same as you can roleplay being addicted to drugs without the presence of in-game drugs. (I did it for years.)
And people roleplayed being elves for years before there was a game mechanic for it.
You can roleplay fighting without using the PvP mechanics. Though I for one find this odd.
Mechanics, however, enhance the roleplaying experience in many places, and are meant to, it would seem, in all.
-Galen's player
Totally right.
RP is about Playing a Role, pretty much like improvised acting - you have the part, and you play it as the character.
There are different levels of dedication to it, from the person that just makes up a backstory for their character to the person that logs in to play that character in all ways.
Right at the seriously dedicated end of the scale, you have people that act out their character's speech and actions, everything. For people at that end of the scale, having some words or actions foisted upon their character is just craptastic. Control over their character has just been compromised to deliver some hammy stock line from a localisation table.
Of course, they don't have to drink alcohol. But why should they have to stop doing something they've been able to since the beginning of the game in order to mitigate it?
Especially since you'll probably find that the RP communities are the ones most likely to use the alcohol in the first place, and long run.