Jon Udell's essay "The wrong end of the telescope ?" raises some interesting issues and summarizes some thoughts from several sources.
They all go to illustrate how difficult it is to put a simple application into a browser page. A part of the problem is that the browser/http/web server combination was never designed to support the rich applications we are trying to shoe into it. Therefore the issue is not really different ends of the telescope but rather different telescopes. Programming the browser is very different from programming the server and they do not connect very well.
The problem lies in the marked impedance between the browser model and the server programming model. Server side programming is relatively easy - the tools are there and it is up to the practitioner's to use them correctly.
To match the server side interfaces with the client is hard when you go beyond a simple form. Entering the world of multi-page applications becomes challenging to say the least. We have invented all sorts of interesting work arounds/add-ons - cookies, frames, iframes, DHTML etc to try and make it possible to deliver rich applications. Some people have created neat frameworks to help such as this from cross-browser.com but in the end the complexity remains in connecting the back to the front.
A good indication of the overall complexity is the number of attempts to build easier to use frameworks - everyone has made an attempt at creating either a new scripting language, a new template framework, a new application stack, application builder and now rich clients. The
proliferation of these tools is a symptom of the problem- sophisticated web applications are too hard to build. The reason is, I believe, there is a impedance mismatch between the browser and the server - HTTP is not the issue.
Sometimes it feels like we are all using different telescopes to hunt for the most elusive thing of then all - the easy model of building, debugging and maintaining sophisticated and usable internet applications.