We can make operating systems where the islands can interact. Its just needs to be opt in instead of opt out. A bad Notepad++ update shouldn't be able to invisibly read all of thunderbird's stored emails, or add backdoors to projects I'm working on or cryptolocker my documents. At least not without my say so.
I get that permission prompts are annoying. There are some ways to do the UI aspect in a better way - like have the open file dialogue box automatically pass along permissions to the opened file. But these are the minority of cases. Most programs only need to access to their own stuff. Having an OS confirmation for the few applications that need to escape their island would be a much better default. Still allow all the software we use today, but block a great many of these attacks.
Sound engineers don't use lossy formats such as MP3 when making edits in preproduction work, as its intended for end users and would degrade quality cumulatively. In the same way someone working on software shouldn't be required to use an end-user consumption system when they are at work.
It would be unfortunate to see the nuance missed just because a system isn't 'new', it doesn't mean the system needs to be scrapped.
> In the same way someone working on software shouldn't be required to use an end-user consumption system when they are at work.
I'm worried that many software developers (including me, a lot of the time) will only enable security after exhausting all other options. So long as there's a big button labeled "Developer Mode" or "Run as Admin" which turns off all the best security features, I bet lots of software will require that to be enabled in order to work.
Apple has quite impressive frameworks for application sandboxing. Do any apps use them? Do those DAWs that sound engineers use run VST plugins in a sandbox? Or do they just dyld + call? I bet most of the time its the latter. And look at this Notepad++ attack. The attack would have been stopped dead if the update process validated digital signatures. But no, it was too hard so instead they got their users' computers hacked.
I'm a pragmatist. I want a useful, secure computing environment. Show me how to do that without annoying developers and I'm all in. But I worry that the only way a proper capability model would be used would be by going all in.