Okay, I know the Real World answer to this question is that there was no way anyone could conceive of wireless networks on the wide scale like we have today back in the mid seventies. Plus the viewer needs a hook, some kind of action that R2 is accessing the computer - the same reason that a Dalek rocks back and forth while talking. So - something occurred to me just the other day - why the hell is R2D2 still using a direct physical connection to whatever computer interface he's plugging into? With thousands of years of technological advances, with faster than light drives and ray guns and laser swords and artificial intelligence built into coffee makers and toasters, surely they have Wifi technology. Why aren't astromechs using wireless? Does the Empire have such a massively impenetrable firewall on their Death Star servers that you need to physically plug into them to access them? Is it because SO much data is flowing back and forth that you need a hard connection to speed things along?