The home washing machine is a complex mechanism that has a variety of settings. I'm sure that some women are ovewhelmed by the number of options and settings and just leave the thing set to run at fast/fast mode. I don't need my dress shirts to be roughed up as much as my socks and underwear, that's why the machine has different settings.
Here is a video and an iPhone app that can help you figure out if your machine is achieving the proper number of RPM's (that's revolutions per minute):
I hope this helps any women who were wondering what the different settings are for.