What about tabs? SPA can make tabs troublesome. If I can't open a site in tabs it is broken to me.

I'm not sure when/why tabs should be an issue... it depends. To me it's a difference between localStorage and sessionStorage for the most part.

If links don't fully address an item then opening it in a tab won't work.

That isn't a limitation of SPA or browser based apps though. For that matter, even having an option to open an app multiple times is often a limitation of desktop apps. That doesn't make them somehow deficient as a platform.

It does. You don't open the "app" multiple times, you open lists or records in separate windows and/or tabs. That is a thing in desktop apps also. SPAs usually break it by tunneling everything through a single url, perhaps with anchors.

But opening lists/records in another window/tab isn't a limitation of the browser environment, or SPA in particular. With proper router/caching in place it can be done within a browser app as well.

Browser-side routing/state management is a solved problem - SPAs can make tabs troublesome if the developer didn't put in the effort.

For God's sake, STOP trying to re-implement my browser's interface with Javascript! I don't want you to "put in the effort" to make my URL bar, back/forward buttons, and tabs work the way they naturally do in my browser; that's what my browser is FOR! Even when the developer does put in the effort, the results are usually _just_ different enough in various subtle ways from the browser's native behviour as to be annoying.

Just build a normal website and let my browser do what it was built to do. The APIs that allow SPAs are great and useful. The Pixlr online photo editor has a good reason to be a SPA, and that works great for it. Your forum/email interface/management API would work better as a normal website.

> Your forum/email interface/management API would work better as a normal website.

Good for you with your fast, always-on internet, I guess. Some consumers have to deal with expensive and unreliable 3G internet (that downgrades to 2G occasionally) - an offline-capable email (or management) SPA is indispensable for them. Sure, you could write 4 native offline apps for MacOS, Windows, iOS and Android but that is a bigger investment than targeting browser standards.

SPA is orthogonal to storage, nor are lightweight web techniques exclusive to it, and often in opposition. Native email clients already exist of course.

Using web API means tabs work even if the developer doesn't put in the effort.

Having the address bar behave sensibly is one of guiding principles of the Ember JavaScript framework. A good modern SPA framework should be able to handle proper routing out of the box.