[thought_alarm]

The reason it's not normally a problem is that if you're working on a document and you hit ⌘Q (or ⌘W for that matter) you will be prompted to save your changes.

However, this does become a problem in web browsers and file browsers where there are no changes to save.

Apparently in the early days of OS X the NEXTSTEP guys wanted to add a ⌘Q shortcut to Finder, which would log you out of OS X. As the story goes, some people at Apple really hated that idea, so after some lively debate they settled on ⌘⇧Q instead. (As a bonus, it's now a global shortcut, so you don't have to be in Finder to use it.)

Similar problem with web browsers. You can give it a different shortcut, or you can enable a prompt to warn when closing multiple tabs. Most people opt for the latter.

[metageek]

In System 7, I think it was, it was possible to use ResEdit on the Finder to add a ⌘Q. Useful if you were low on memory. IIRC, if the last application exited, the Finder would restart.

[parenthesis]

In earlier versions of OS X (<= 10.3 (?)), ⌘Q when in the Finder quits it, just like any other application, which was a little disconcerting the first time you did it (by mistake).

[philwelch]

This wasn't the case at all, at least not on stock OS X (who knows what you could enable with haxies). You could certainly force quit the Finder, but it just relaunched immediately.

[parenthesis]

Well, that's funny, because I'm using vanilla OS X 10.3.4 right now, and I just quit the Finder in the way that I said.

Screenshots:

http://www.alexmaslin.org/quit-finder.jpg

http://www.alexmaslin.org/no-finder.jpg

It doesn't relaunch automatically. You either have to click on the Finder icon in the Dock, or otherwise it relaunches itself if you quit all other open applications.

[philwelch]

That's extremely funny, but I'm almost completely certain that's not as "vanilla" as you think it is. Perhaps it was enabled on the command line? It looks like

  defaults write com.apple.finder QuitMenuItem -bool YES

will do the trick. So perhaps you're operating from a custom com.apple.finder preferences file.

[parenthesis]

Yes you are right. I have absolutely no recollection of tweaking this, but it seems it has been done. (I just checked a different, definitely unadulterated 10.3.x install, and it doesn't have the Finder quit menu item.) Thanks for correcting me.

[bconway]

I had this issue for a while, and got around it by requiring Firefox to prompt me if I'm closing more than one tab at a time. It's ugly, but it works.