Unity is also notoriously painful when it comes to 2D UI style work as well, which is why there's a tools ecosystem around it just to deal with that problem.
Saying that the apps generated don't look "native" doesn't support the assertion that WORA is a "failure". Doubly so considering the ubiquity of Java.
Otherwise it sucks.
Well the web doesn't have a native UI. But iOS and Android DO have one.
While the applications are other way around. New customers do not want to spend more than a minute to get familized with the interface. Moreover, your custom UI interface will be competing with Apple/Google designer's budget.