I fully understand how much the world has invested in making the web into an applications platform, and I recognize that many things of value have been built on that platform. But it's been a fundamentally flawed enterprise from the start, and the pitfalls are getting harder to ignore. We need to start taking seriously again the idea that untrusted code cannot be trusted. We need to stop re-inventing the operating system within the browser just because some programmers are too lazy to port their applications to more than one OS even when there are libraries to abstract away all the differences that don't require a UI redesign. We need to stop sacrificing so much efficiency for the sake of portability that doesn't live up to its purpose.
In order for a web browser suitable for document-oriented usage with limited interactivity to be secure and offer reasonable protections for your privacy, it has to take measures that preclude it from being a good applications platform. That conflict seems irreconcilable.
Don't be ridiculous. I'm not saying we shouldn't have cross-platform apps at all. I'm just saying we need a clear distinction between the WWW and any applications platform, just like we need a clear distinction between sidewalks and freeways. The web browser cannot do both jobs well.
One problem is, no one seems to be able to define "web application" in a way that makes the distinction clear. Most sites that use javascript still use it in the context of displaying documents, so if you define any site that uses javascript at all as an "application," then most sites, including Hacker News, count as applications. But that doesn't actually fix any problems.