They did that to stop piracy. Too many copies and too many discs being shared. That was eating at their profits. I personally prefer having Google maps than a proprietary GPS system. And real time updates versus waiting a year. There's aftermarket options to replace the stock system for a modern Android based one with Google maps, etc. Mostly great reviews, some quirks but might be still worth pursuing.
Hard to say if you can just plug and play. There's two components. There's a screen and a controller assembly. Now the question is where the data resides. I know that anything surrounding these systems usually requires programming. Programming is done using a proprietary Nissan/Infiniti laptop called CONSULT 3. Nissan/Infiniti won't touch anything that's not stock or modified per policy. Unless you can find someone who's willing to do it. Or know a custom shop that has that super expensive laptop. Be cool if someone had the means to swap in another screen/controller assembly and report back.