The thing about doing it "web based" is that you get to take advantage of the fact that browsers already know how to understand markup (ie, various types of formatting), and most browsers have built-in "print" functions for creating hard copies.

This enables the developer to ignore issues such as dealing with printer output, dealing with event handlers, Tk callbacks / window management, etc.

So the development time is greatly reduced, while being able to present any feature a browser is capable of offering. Look at it like someone's already created an easy to use interface system. Yes, you still have to design the HTML that drives the interface, but that can be trivial as compared to dealing with a full fledged GUI.

Designing an application, and choosing to make it web based (intranet, etc.) is simply a design choice whos goal is to provide a lot of features with a minimum of development effort. Yes, a desktop based software package can be made to look even more polished. Heaven knows, nobody would really like to be forced to manipulate a web-based interactive spreadsheet. Nobody's going to suggest trying to come up with a web-based alternative to QuarkExpress, or Aldus Pagemaker. But if the objective lends itself to a web-based environment, there are good arguments for going that route.