In all my years of working with text editors, I don't think I've ever found myself thinking "This viewport is too small. I wish I could quickly resize it to just the width of the text, and maybe the height of the screen, or maybe something else, depending on what I'm doing." When my window is too narrow or whatever, I usually just (a) maximize it (which you can't to on osx), (b) dock it to half the screen (windows+left or windows+right on Win7+/*buntu, but not on osx) or (c) just quickly drag it over. So Apple effectively forced us to use only option (c), which is probably the least useful of the three sane options. The only other option is to use a feature that doesn't really do what we (or I, anyhow) want.
I use Sublime Text 2 on OS X. When I click on the zoom button, it maximises the editor window to the entire width and height of the screen.
Amusingly enough, the only things it doesn't really work well for are things that reflow their content arbitrarily to fill the window: text, HTML, and terminals. The three things developers spend all their time looking at!
The worst example of where this doesn't help is the Zoom button. Not the maximise button, as it's never been called that, and doesn't actually maximise - it resizes the window to the most useful size. For example, my BBEdit window gets resized to the width of the text, but the height of the screen. Of course, many apps just make it fill the screen (incorrectly), leading to the 'maximise' button instead.
(Also, you can command-click on a window title to get a menu that allows you to go up. Two clicks instead of one, but it's there. This works on folders, files, and URLs)