First, let's address why. Scotch is a higher status drink. Among the myriad of preposterously wrong characterization Bruce Wayne is subjected to in fan fiction (and some pro stuff, sadly) tons of it comes down to social class and not understanding the fundamentals of the world he was brought up in. Lesson 1: Drink dry. To put a wine cooler, a sloe gin fizz, one of those foamy milky things, or a glorified slushy in Bruce Wayne's hand is to have him declare that he loves magic and Joker isn't such a bad guy once you get to know him. (Conversely, when Matches Malone enters the picture, he's going to design Matches's lower class tastes from the perspective of his own patrician ones. Enter the "bourbon and ginger" or "seven and seven.") This part is not affectation, it is a simple matter of taste as it evolves if you grow up in Wayne Manor, Bristol and not 510 Kathy Street. But then you add in the affectation when Bruce is playing the fop. Good scotch is not only expensive, it offers a wonderful opportunity to play the snob, the connoisseur whose expertise comes down to reading the prices and choosing the most expensive, a militant about specialty glasses and decanting methods without having the first idea why these items and methods are preferred. A single malt scotch, with a side of Scottish spring water to back it is the Fop gold. It's expensive, conspicuous, and fills the table with fop props.
Harvey, naturally, got assigned scotch as his beverage of choice so Two-Face could order a 22-year old double malt, and later, pre-acid Harvey's fondness for single malts was a nice way to torment him a little more after the acid. Yet another thing he used to enjoy that TF took away from him. Eddie's preferred tipple is Glendundrom just because I wanted a quasi-rhyme for conundrum. That said, part of every artist's job is finding a retroactive rationale for whatever we want to do for artsy reasons, known in theatre design circles as "bullshitting."
While Harvey isn't quite in Bruce's league, he was born to privilege. Most American politicians are, particularly the ones starting the process as high on the latter and as young as Harvey Dent did. Eddie is quintessentially middle class and they tend to ape one tier up. So he's covered.
Now that's why those 3 drink scotch. Tomorrow we'll get into what it actually is.
