What I am about to tell you may endanger my own life.
There are a lot of theories as to what happens to odd socks that don't come out of the laundry. Malicious gremlins, spontaneous existence failure, and inadvertant shrinkage to microscopic levels have all been proposed, with varying acceptance. Some people cite the fact that putting all your socks in a sealed cloth bag apparently prevents them from going missing as evidence for either the "quantum indeterminacy" or the "human carelessness" hypotheses. All of these theories are wrong however, for I have learned the shocking truth. Exposing it publically may well be the only great achievement of my life, and I am sorry to say it is likely to be my last. But the world deserves to know.
You, dear noder, deserve to know.
You probably believe your washing machine functions by filling a giant bucket with water from the mains, optionally heated, and swooshing your laundry around in it until all the dirt comes out. You've probably never really given this process much thought beyond how long it seems to take and how much it seems to put on your electricity bill. You may even have tried washing your clothes by hand, and if you're the observant type you may have puzzled over how your clothes never seem to come out as clean when you do it this way, despite using the same detergent, the same hot water, and hands that are in theory considerably more effective at agitation.
The answer is that washing machines do not function this way. The noise, the vibration, and the wet clothes are just a cover story to conceal the true mechanism: a tame black hole! The laundry goes into the basket, and the black hole is moved upward to just underneath it; the dirt is them violently sucked out through the little holes, which acts as a sort of sieve. Occasionally, dye particles can get sucked out too, or into other pieces of clothing below them. You've probably already leaped ahead to the conclusion that socks can get sucked through the little holes; in fact any of the smaller items of clothing can slip through under the tremendous gravitational pull. Socks just get missed more often because they come in pairs! You've probably lost more than a few knickers/boxers this way as well, but what kind of sad sack counts their knickers? The reason bagging the socks keeps them from going missing is because a whole bag of clothes won't fit through the little holes, even when pulled very hard. You may also have noticed that big, thick woolen socks go missing less often as well - same reason. It may further explain why you occasionally find socks in your laundry that aren't even yours, but I'm not an expert in black hole physics so I can't comment, and my source was silent on this issue...
But surely this is a ridiculous notion? What could the motivation for washing machine manufacturers possibly be to keep this a secret? The answer, it pains me terribly to say, is a conspiracy! You see, black hole washing machines don't actually consume any more electricity than it takes to power the fake vibration unit and the Sloshing Simulation Module (SSM) - certainly not the kilowatts of power that end up on your electricity bill. The reason you're still charged for it is the electricity companies know you don't know how your washing machine really work. The cable at the back - you know, the big thick special cable only washing machines use - is actually a direct communication line to them - they bill you for the amount you would have used if it were a "traditional" washing machine, and get away with it too! This is why it's still a secret, and it's no surprise profit is at the bottom of it.
You're probably wondering how I found all this out. I can't tell you, to protect the innocent scientist who was clever enough to deduce all this, and courageous enough to tell me (envoy to the internet's most trusted repository of knowledge) in spite of the risk of further terrible retribution (for he has already suffered terribly at the hands of the shadowy powers at the nexus of this conspiracy - full body paralysis is not an easy thing to live with). After all, there aren't many black hole physicists in the world, and if I divulged too much information it could probably be deduced who he was.
All of this applies only to top loaders by the way.