The fragility of in-band signaling in the TTY world is not *nix's fault or anything. VMS had that too, since VMS too had to deal with TTYs. The fact is that a) the system evolved from real, hardware TTYs of the 1970s, b) using a text stream with some in-band signaling doesn't even half suck -- mostly it rocks, and all you have to do for it to rock is get the right $TERM value and not output binary files to the tty.
Hints:
* You have the wrong country, on the wrong continent.
* It's not as simple in reality as your first answer will be. (-:
I mean, both approaches have their pluses, but the API approach is only ever going to work well for remoting if it is standardized and interoperable. And the installed base of Unix termcap/terminfo programs is huge, so plain old text-with-in-band-controls is not going away anytime soon.
The difference is important, since in the traditional MS model, each program that wants to do the remote thing needs to essentially implement its own client-server setup, albeit with a massive amount of help from various runtimes. Named pipes and central authentication made this approach not quite as horrible as it sounds.
This new API is a departure from this model. It will make it possible to just remote via text streams. Perhaps that's uglier --- everyone knows in-band signaling is fragile. But long experience shows they just remoting the damn text streams is easily the more pragmatic option.