I agree that html freedom has done a lot to user interfaces and ux. But that works best in a web setting.
In an intranet setting (the kinda place where IE6 may still linger for 2-3 years) using standardized RIA frameworks like ExtJS help speedup the development cycle by offloading 80% of the design work from the 1000+ developers, which probably already have a handful trying to figure out in which order a certain financial transaction needs to be called on the Mainframe CICS-DB2.
I spent the last ten years writing intranet apps and evaluated and rejected EXT and similar frameworks several times because it just didn't meet our internal users' needs. They preferred our lightweight interfaces that rendered quickly and well on all kinds of different devices.
However, our environment was a little unusual in that we were able to mandate reasonably modern browsers (FF 3+, Webkit).
In an intranet setting (the kinda place where IE6 may still linger for 2-3 years) using standardized RIA frameworks like ExtJS help speedup the development cycle by offloading 80% of the design work from the 1000+ developers, which probably already have a handful trying to figure out in which order a certain financial transaction needs to be called on the Mainframe CICS-DB2.