oooo what a good thread, ff!
there are several reasons; machines are the product of man, come from men, and are under man's control. As they have no intrinsic gender of their own, they are given a subordinate one to men, so that's traditionally the role of women. I'm not saying that's the way things are or ought to be (one can only dream
) but that's the extension of the thinking behind this tradition.
many of the mundane tasks that were mechanised during the Industrial Revolution were undertaken by women, hence the Spinning Jenny.
Many machines/machine types have become so wrapped up with male ego and chauvinism that its almost impossible to consider them otherwise. Could you relate to a sports car or power boat if you thought of it as male? Err no, I couldn't. The concept of "going for a ride" becomes abhorrent, does it not?
I'm sure there was another reason too but I'm a bit tatered tbh so I can't think of one right now.