This advice sounds more like sour grapes disguised as best practices. I believe a similar excuse was trotted out with Swing ("Swing is it's own platform!"). Users didn't care, they hated the non-native, slow, accessibility-unfriendly Swing apps, which they perceived as bloated and low-quality largely due to the feel.

I can't help but chuckle at the fact that we're making literally the same mistakes we made eight years ago while claiming progress.