> "Non-native" is not always a bad thing.

Setting aside the non-native look and the non-native feel, one reason it's almost always a bad thing in practice is because developers who re-invent everything rarely match the accessibility support of the native platform.

I believe that this applies not just to the front-end development, but also the back-end frameworks and libraries.

I've seen people attempt to create their own (oftentimes poorly documented and poorly tested, as well as poorly supported) web frameworks even in large projects far too often.

It seems that for any project that needs to be supported and maintained for years if not decades, the argument could be extended to: "Non-native and non-standard is usually a bad thing."

Of course, there's nothing wrong with using bleeding edge technology and writing your own frameworks and libraries, however that should only be done when and where it makes sense.

We're all lazy. That's why we got into this profession.

Non-native look and non-native toolkit is two different things. You don't need to look native to support accessibility, built-in i18n and L10n, to behave like other native looking applications. But you certainly need to be native to not stick out like a sore thumb.