If fully open processes worked here, the W3C never would have been founded. But I was involved in HTML 2.0's development there, and saw HTML 3.0 fizzle and die, and the simple fact is that the open process was ignored by the most influential players and became irrelevant. Servers are infrastructure. The Open Source community is good at infrastructure. Apache dominates the server world.
Browsers are consumer applications.
The Open Source community is not very good at consumer applications. Microsoft now dominates the browser world, as Netscape did before them. HTML, XML, CSS, XSL, and PNG are controlled by the W3C. That said, the W3C is much more open than it has to be. But it's frustrating when you can't see the inside, and philosophically upsetting that an open process failed. The only way I can see for this to ever change is if an Open Source browser were to become dominant, and I just don't see that happening within the next five years.