Why Can't We Disable the Alt Key?

I would like to share a frustration with the rest of you. Why can't we disable the Alt key while we're typing? I am getting so fed up with the stupid thing that I would like to rip it out of the keyboard. I just spent a half hour composing a blog entry, and in one second with a fat finger to the ****ing Alt key combined with an unfortunate tap on whatever key I was using, my browser window shut losing my half hour of work. Note, when Firefox brings up the dialog asking you if you want to close all of your tabs, hitting "cancel" does not work! I lost the whole thing.