The Dying Bastard is the middle child of the Bastard trilogy, a lime-juice-and-ginger-beer family of drinks with an increasing number of spirits.
Since there are three base spirits in this drink, plus the strong flavors of bitters and ginger beer, it doesn’t really make sense to use a spirit with subtle flavors, like Hendrick’s gin or a finely-aged bourbon. The drink was invented by barman and legend Joe Scialom during a period of WWII liquor shortages, and it’s probably fair to say he wasn’t using his finest bottles.