And remember, once you think that shit is working and do decide to go native, you’ll still need a great web experience for user acquisition. The first experience most users have with your product will usually be when they land on it in browser. If your app is amazing, but the web app is half assed, potential users will only see your app as half assed.
Imagine the experience you would like to deliver to your customers.
Now, do the hard part. Imagine the experience you want to deliver to your customers, at scale, when your service is incredibly successful. If that involves more than one computing platform, you need to consider the web, as a potential method to scale and target all platforms.
Bonus points where you feel the web does not allow you to deliver the experience you want to and you can affect the change as it will potentially help millions more to deliver similar experiences.
Finally, a note on "smooth, 60fps animation" as a "native" attribute.
Writing great applications for the "open web" is no tougher than writing great native applications (in fact, some might argue, it could be easier). However, much like it is easy to muck up a native app, you can muck up the web app too.
The development stack and profiling systems can (should?) evolve and make it even easier to achieve the great experiences for applications written to work across multiple platforms (and the browser). And I think the open web is going to get there sooner, than later.
I am long open web. :)