It turns out that it’s a lot of work to do it right. You first have to build a boring version of your app (which as my friend Sean explains, is inherently less than). Then you add frills. And now whenever you want to fix a bug or change a feature, you have to make sure everything still works in both versions.
That sounds not simple for the developer. Yet, this is a time to ask, simpler for whom? Because when done right, like the GMaps team has, the solution is very elegant for all users.