Ha, I've been following this whole thing and it's just so funny to me. It's such a younger generation thing, maybe I'm older and so I've just "played the game" a lot. The whole thing is _should_ you be able to take your drink of choice? Of course! However, would I do that? Hell freaking no I wouldn't.
Going into an interview from the first glance they're judging you to see if you're a good fit. Granted you're also judging them but let's be honest, it's pretty lopsided. If I go in I'm putting my best foot forward and I want them to see my best foot forward, it means I'm putting on a show for the next hour (or more nowadays) so that you want to hire me. I'm not bringing in anything that alters that view of me. Iced coffee, hot coffee, nothing. I plan ahead, I'll usually be at a coffee shop before the interview anyway (it helps make sure I'm there on time, get there 30-60 mins ahead of time and chill at a coffee shop), and then walk over for the interview.
Bringing a drink or anything extra is just something that now they're thinking about, and you don't want them thinking about you in that way. It's something else that you put on the table, you're taking sips of, for cold drinks it's condensing and leaving a ring, and then you have to ask for a trash. All benign things but again, you're in their house and why would you want to bring any negative attention at all to them? I've had interviewers who were obviously just having bad days say no to me for arbitrary bullshit already, why add to that? It all seems like an unnecessary gamble for no reason at all.
Now if they offer coffee or a drink when you get there (hopefully they do) I'm all for it. They offered, it's free game. Go wild. Just don't get picky.
I know this is a wall of text but I'll also say that as an interviewer I don't care at all if they do, as long as they're professional and it doesn't get in the way. If it's distracting, you're shaking the ice, or slurping out the last bits, or whatever, yeah it's going to distract me. I'm not going to be annoyed because you brought coffee, but I will be annoyed if you aren't appearing to take an interview seriously.
