The HTML browser was never designed to do the things that we expect it to do on a daily basis.
It's so interesting to me that Alan Cooper was writing the first edition of his amazing book About Face the web was taking off, destroying all aspirations of good user interface design in its path. Now we are back in the equivalent of the mainframe terminal era, albeit with graphics, and the amazing thing is... we're OK with that!
I think we will soon though.
The web is really starting to stanardize on page layout, menu positioning, etc... people now expect certain things from web sites and as these standards evolve I think we will see more tools specifically designed to take advantage of that standardization and then we will be in a position to make some real progress in UI design again.