GUI development in HTML/CSS + Java – GWT in a new way – JBoss Errai framework

JBoss has a web framework named Errai that has a quite interesting design - http://erraiframework.org. For example it allows sharing validation code between client and server.

It includes HTML based tempting, bidirectional binding, integration with JAX-RS, bookmarkable Urls, a distributed event bus, mobile integration, and client-side JPA for online storage.

My understanding of Errai: It's meant for frontend development directly in HTML/CSS and uses Java as a replacement for Javascript. It uses internally GWT but only the compiler and does not include the GWT Widgets hierarchy of components, that has been used in many projects to allow doing frontend development in a object oriented-centric approach.

That GWT object oriented approach seems to have been historically introduced mainly for IE6 support, as the same HTML/CSS did not look at all the same in IE6 and other browsers which was a deal breaker for using those technologies directly in many enterprise applications.

Today in ever-green browsers the object oriented approach ends up acting more as a not always wanted layer of indirection to HTML/CSS more than help solve browser quirks that are no longer present or that can be solved more easily in other ways (for example by using CSS frameworks such as Yahoo Pure CSS).

Errai also does not include GWT UIBinder that allows web development in a mixture of XML and HTML.

The framework has been around for several years and it’s at version 3, here is a talk on it -> https://www.youtube.com/watch?v=rz2X667Wk_4#t=850

Does anyone has experience with it, comments on the design or insight into why it did not gain more traction until now?