You mean programs could access the file system normally? They were absolutely isolated as standard unix processes.

This is what I mean about iOSification - it's trending towards being a non serious OS. Linux gets more attractive by the day, and it really is the absence of proper support of hardware in the class of the M series that prevents a critical mass of devs jumping ship.

The only Unix security boundary is between users. There isn't a standard boundary between "a web browser tab" and "the file with your credit card info in it".