Remember Flash? Narrow the gap, add a bit of Steve Jobs and Boom! The web Won.
Look at a site like YouTube today. All the tooling we've created and all the progress of the open web platform that has made that site happen is incredible. If we've just given up 10 years ago, saying to ourselves that the web should only be for documents, then we would be missing out big time right now.
It’s not for every site to try and push the envelope. And mimicking native can often lead to bad results. But to go from that and say that we shouldn’t try. That’s just sad.