This "your UI shouldn’t mimick [sic] the native style of the platform" advice reminds me of what we used to hear when using Java and Swing a decade ago. It resulted in a bad user experience then, and I think that still holds true today. Swing apps never felt right on any platform, even when using a native theme. It's probably no different for apps built using Cordova, too.
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.