It's not ironic, it's conscious. The typewriter was the blue print for the app. It was supposed to be called writing machine (from German Schreibmaschine = typewriter).
Writer seems, conceptually, like using an old ibm word processor (remember those with the one/four line text display that would then typewrite that onto the page?) It seems like a sophisticated version of that. maybe with the new printing in ios 4.2, you could make a usb-teletype that would print out the document you had just written. (aside: i would love a usb-teletype printer)
still, props to y'all for making that leap. i don't have an ipad, otherwise i'd probably have some other comments.