I'm probably going to get all kinds of feedback on this one, likely ranging from "Amen!" to "Heresy!" but before you sharpen your keyboard, let me say one thing: the martini is way more flexible than you might think.
Nowadays it's typical to order one of these in a bar and be given a glass of something clear and cold—a large, chilled pour of gin or, let's face it, vodka, with nothing in it except a massive olive or three. With all due respect, that's not a martini. That's just cold booze, and there's no shame in ordering that if that's what you want.
But for at least the first five decades of its circulation, ever since a drink with that name and this general description first appeared around 1900, a martini required vermouth—a lot of it, none of this atomizer business or that stale "glance in the direction of a vermouth bottle" hokum. And early on, much of the vermouth making its way into martinis was of the sweet Italian variety rather than French dry—hence, a "dry martini" was a drink made with dry vermouth, not one with as little vermouth as possible.
Bar guides and newspaper descriptions published through the 1940s and into the 1950s described martinis as a mixture of two parts gin, one part vermouth, many times with a dash of orange bitters (don't knock it 'til you've tried it) and a lemon twist, and there were variations on the theme, with differing proportions and styles of vermouth. It wasn't until the Mad Men era that the less-is-better approach to vermouth really started catching on.
In The Hour, a cocktail manifesto by Bernard DeVoto, first published in 1951 (a new edition was released last month), this legendary curmudgeon describes his ideal martini as a 3.7:1 ratio of gin to vermouth, a proportion that would be considered drowning in the aperitif by today's standards but at the time was the cutting edge of dryness in the drink.
Whatever; mix it the way you like. If you prefer your martini with only the merest whiff of vermouth, then go for it, or if you like it up to equal parts gin and vermouth, there's a firm historical foundation (not to mention a culinary one) for going that direction.
