Humans have a longstanding tendency to anthropomorphize the objects and appliances we use—boats, cars, computers, even electric drills and washing machines. Think of a device, and someone out there has probably given it a human name.
It's a habit that explains the way humans see their relationships with machines—that is, your relationship with the individual machine you name, and the larger fact that machines do the jobs that humans once did.
In an Oxford English Dictionary blog post, Peter McClure looks back at centuries of human-named machines—the devices that get human names that don't reflect the names of their inventors—as one part "an extension of the sense 'servant'" and otherwise purely anthropomorphic.
'Malkin' has already been mentioned as a word for a long-handled mop or sponge. The spinning jenny was first so called in 1789. Jemmy, first recorded in 1811 as ‘a burglar’s crowbar’ is from a pet form of James. Any contrivance that turns, lifts, or holds stands a chance of being called a jack while Tommy... has been widely used to denote workmen’s food, especially bread. In the sense ‘something small of its kind’, both jack and tommy are used to denote small devices—such as sockets, levers, spanners, and wrenches—or other small objects like the jack in a game of bowls or the flag flown at the bow of a ship, the origin of the Union Jack.
And though men's names are occasionally used to christen "powerful mechanical contrivances" like engines, gigantic bells, blast furnaces, and wind turbines, McClure points out that enormous machines and great guns are often named after women—a trend that has "interesting psychological implications" that underscore the standing of women in society, men's ideas about how much control they can wield over women, and so on. Here's the "Big Bertha" howitzer:
This generator, which also earned the nickname "Big Bertha," is at a California Air Force base:
This Mons Meg cannon, at Edinburgh Castle, is about 500 years old:
Frontiersman Davy Crockett famously owned rifles he called "Old Betsy," "Pretty Betsy," and "Fancy Betsy." Actually, even the word "gun" appears to have come from a woman's name, McClure says.
A siege engine, in the form of a giant crossbow, was named Domina Gunilda (‘Lady Gunild’) in an Anglo-Latin document of 1330-1. However, the usage probably goes back much further. Gunnild was a well-known female name in the twelfth century but was obsolescent or obsolete by 1250. Shortly after 1300 gonnilde appears as a word for a cannon (a1325 in the Middle English Dictionary) as does gun, from the pet form gunne (1339 in OED).
From gun comes gunner ‘a cannoneer’ (1334 in OED), but a much earlier example appears in the surname le Gunner (1238-9 in a Dublin Guild merchant roll), which may alternatively have meant ‘an operator of a siege engine.’
Anthropomorphizing our machines is a way of commenting on the kinds of jobs they do, but it's also a way for us to express trust in them—which, of course, has everything to do with our comfort level and nothing to do with a machine's effectiveness. Your computer doesn't care if you call it Siri, or Hal, or Joe. But you might be more likely to ride in a driverless car if the vehicle seems cute in a vaguely pareidolic way.
Giving something a human name is ultimately, then, a way of exerting control over it—a reminder that it works for you, that it exists within a human construct, even when the machine itself is wholly indifferent. This is why we give human names to all sorts of things we can't control in nature—Hurricane Hugo and Jack Frost and "Tommy long legs," the popular nickname for the spiders many people now call "Daddy long legs."
Machines don't need names, but we feel the need to name them—out of a mix of affection, perhaps, but mostly out of a desire to reorganize forces more powerful than we are so that they appear to be under human control. Whether or not they actually are.