There are numerous requirements that must be met that make it impractical to produce spirits on a small scale. Some of these requirements are paying multiple special taxes, filing an extensive application, filing a bond, providing adequate equipment to measure spirits, providing suitable tanks and pipelines, providing a separate building (other than a dwelling), getting proper zoning approval, maintaining detailed records, and filing reports.
It's really quite obnoxious and involves as much red tape and unnecessary expenses as I feared (e.g. placing a bond?!) So this is why we never see "Jim's Vodka" on the shelves of the local Liquor & Wine or see anything really unusual at the supermarket, the only way for a distillery to be profitable would be to produce thousands of bottles a week.
Which is interesting, because with only huge factories able to bring their product to market, you start getting the movie industry phenomenon where there's so much money at stake they refuse to take risks, and the whole industry becomes swamped with bland middle-of-the-road products.
I also learned that distillation factories actually produce rather poor alcohol from a scientific standpoint as their setups are designed around speed and quantity rather than purity. For instance, factory booze has a lot more methanol (a poison) and fusels (contributes to hangovers, tastes bad) than the average ghetto moonshine setup. The percentages of these contaminants are rather small, well below that which could actually hurt you, but you'd think that a cleaner booze would be better for consumers.
This doesn't necessarily mean that the idea of a ginger vodka is dead. The actual distillation process isn't difficult or expensive at all, only the red tape is. One could say, build a small still -- as a hobby -- and give away interesting concoctions to friends and family.
Everyone loves outlaw hobbies.