I find it endlessly fascinating (and perpetually frustrating) that 26 years after the introduction of the Mac, all of us -- on Windows, Mac, Gnome desktop, pretty much you-name-it -- are still suffering with the same tired UI metaphors in our desktop apps, some of which continue to serve us well, but others of which continue to serve us shoddily, day after frustrating day. The UI metaphor that serves us most shoddily of all, arguably, is that of the modal dialog.
I'm starting to agree with Aza Raskin and others who have pointed out that modal dialogs (dialogs that won't go away until you deal with them) are basically evil. They're not dialogs at all. They're more in the nature of monologs. A programmer has decided that you need to stop what you're doing and focus on (and make a decision regarding) whatever it is the programmer has decided you need to focus on, before you can move on to something else. This is done for your own good, of course. God forbid you should defer a decision, or decide to go on working while making a decision.
Some modal dialogs are necessary, of course. After all, if it is a requirement that you enter a license string before using a product, then you damn well better enter the license string. But most modal dialogs don't have to be modal -- and shouldn't be, IMHO. Most modal dialogs are modal because it's easier for the programmer if you work that way; maintaining a consistent program state becomes messy and difficult if you have a bunch of dialog boxes open at once. It's a matter of convenience. Not your convenience; the convenience of the people who designed the program.
"Modal" is not how people like to work, though. People tend to be extremely ad-hoc in their working styles (to match their thinking styles), tackling little bits of a job in random order, working a little on this, a little on that, until the job is done. Few people tackle a job by working it linearly, in rigid stepwise fashion, step by step until it's done. That's why wizards are (as UI devices go) generally odious. They don't match the way people work.
In my day job, I have the (dis)pleasure of using Adobe products intensively. The three I use daily are Acrobat Professional, Photoshop, and FrameMaker. Of these, the one I use the most -- and that causes the most heartburn -- is FrameMaker. Ironically, Adobe has learned a great deal about good UI design over the years, but they've applied the knowledge haphazardly. Photoshop, in particular, has become much less modal (as has FrameMaker); you can work ad-hoc now through a combination of always-open dialogs (palette panels), always-visible contextual toolbar buttons, and hotkey combos. However, image filters (plug-ins) are still modal: You work with one effect at a time and can't leave them open while jumping back and forth between them, much less chain them. Ironically, Adobe After Effects does let you work with filters that way (pipelining them; playing with multiple filter settings simultaneously, in non-modal fashion). You'd think Adobe would apply what it has learned from After Effects to Photoshop, for the benefit of the much larger Photoshop audience. But no.
With FrameMaker, palette-style operations are (thankfully) much more the norm now, but there are still far too many modal dialogs, and the ones that are most intrusive (for me) happen at the worst time: when I am opening a file. It so happens that I work with a lot of files that have missing graphics (graphics that are on someone else's machine) and/or unresolved cross-references. It's in the nature of what I do that I'm always encountering such files, which means that when I open them, I always have to dismiss 3 dialogs. The first dialog asks me to locate missing graphics. After I dismiss that dialog, I'm confronted with the following dialog (monolog):
Once I dismiss this monolog, I am confronted with yet another warning:
My question to Adobe is, why do I have to dismiss 3 dialogs in order to open a file? (And go through the same process every day, every time I open the same file?) Why can't you just put this information in a status-bar message at the bottom of the window, or flash it in a tooltip at the appropriate time (when I hover over a missing graphic), or at least put a checkbox on these dialogs that says "Don't show me this again"?
Better yet, give me a global config setting somewhere that turns off all "informational" alerts (see the little 'i' icon in the box?) and converts whatever those alerts (monologs) were going to tell me into log messages that I can look at whenever I want? Why put a modal dialog in my face and make me dismiss it 20 times a day?
But then, maybe I ask for too much. After all, it's only been 26 years now. These things take time to change.