(I wrote the original blog post.)

You're right that things like PhoneGap give access to native features. However, the Native-API-implementations in these frameworks are 1) typically significantly behind the native OS (release date) 2) tend to have less-than-feature-parity

So, often you're stuck writing your own native bridge, or tweaking the portability framework's version, which is time wasted (IMO) vs writing to the native framework. As an example, just try and write a PhoneGap app using Bluetooth: The Android implementation is incomplete, and the iOS version is non-existent.

Also, there are a tonne of performance issues you run into with the HTML/CSS/JS + Framework + Native solutions. As a thought experiment, consider how you'd build Instagram in one of these frameworks.

1) Image filters in HTML/CSS/JS land? Slow. 2) Thousands of images in a continuous virtual scrolling window in HTML land? Slow. 3) Fetching a binary blob (the image) from the OS, and throwing the resulting blob back-and-forth to web-land (for example, to use HTML5 offline storage) ... hellish slow.

Compare that to native... it's just one example of where the theory of HTML for UI and native for logic breaks down when you start to push the platform a little outside it's comfort zone.