Yes. Unfortunately. But honestly, if you're ordering a martini call your liquor anyway. I'd never say "give me a martini please" and pay $12+ for the house gin or vodka.

Maybe if it's a bar that only serves gin . Even at swanky cocktail bars, if you didn't specify they'd probably ask if you wanted vodka or gin. Put another way, there probably aren't many places in the US where the "default" is gin.