The thing to remember is that the Republic and the Empire is vast and has thousands of developed worlds on it. Can you imagine the effort it would take to get data/computer standards in place?
Why isn't Wifi commonplace?
It might be but it's a different standard to the one you use so might as well not exist. Just look at how some American mobile phones won't work in Europe because they use a different radio standard. Multiply this over a thousand worlds and droids talking basic to each other or flicking a switch makes things much easier. Not a bad explanation and just as realistic as hyperspace, laser swords or dilithium.
Star Wars tech is static because it is very mature and it is more a case of repackaging what is available and not making any new breakthroughs.
Plus it's pulp space fantasy and if your players have issues with this then they should be playing Eclipse Phase or similar and not Star Wars