Apart from the rudimentary whiff of vermouth this is effectively straight spirit (gin, vodka or half and half for a Vesper Martini). Saying that, I find that there is a knack to making them properly and the quality of the liquor, stored at a cold temperature, is the difference between either having a sharp sophisticated drink, or a large unappealing tepid puddle of booze.
Old school cocktails like the martinis and the Manhattan are booze heavy and frequently are not to the taste of your average dinner guest (not to say that any of your dinner guests are average).
Matt1 enjoys that he doesn’t need to stop drinking to enjoy a delicious olive.