I agree that ideally, you wouldn't wrap your text manually and your editor would do soft-wrapping, as well as any tools like `git log` or email programs that patches were read with, so the commit message would fit on any size screen.
In the real world, however, lots of people use editors that don't have good soft-wrap support turned on by default, meaning that they're going to be doing hard-wrapping at some width. `git log` does not do any wrapping of messages, so depending on your pager settings you either get the line going off the edge of the screen or being wrapped by your terminal with no regard for word breaks.
Furthermore, even when soft-wrap is supported, it sometimes makes text harder to read; if your window is wide, and it just uses the whole thing displaying 150 characters per line, it can make the text a lot harder to read than a nice narrow column of text. I have this problem on the web a lot; some sites use multiple columns which take up lots of horizontal space (under the assumption that everyone runs their browser full-screen), which makes me widen my window, but then I come across a site that just uses the whole width for one big block of text, which now has unreadably long lines.
Given that many of the tools in question don't support soft-wrapping usably, standardizing on 72-column hard wrapping is a reasonable approach. Lines don't come out unreadably long that way, they will be displayed reasonably in `git log` and other tools on standard-width terminals, and they will display well in 80-column email clients even with several levels of quoting.
In the real world, however, lots of people use editors that don't have good soft-wrap support turned on by default, meaning that they're going to be doing hard-wrapping at some width. `git log` does not do any wrapping of messages, so depending on your pager settings you either get the line going off the edge of the screen or being wrapped by your terminal with no regard for word breaks.
Furthermore, even when soft-wrap is supported, it sometimes makes text harder to read; if your window is wide, and it just uses the whole thing displaying 150 characters per line, it can make the text a lot harder to read than a nice narrow column of text. I have this problem on the web a lot; some sites use multiple columns which take up lots of horizontal space (under the assumption that everyone runs their browser full-screen), which makes me widen my window, but then I come across a site that just uses the whole width for one big block of text, which now has unreadably long lines.
Given that many of the tools in question don't support soft-wrapping usably, standardizing on 72-column hard wrapping is a reasonable approach. Lines don't come out unreadably long that way, they will be displayed reasonably in `git log` and other tools on standard-width terminals, and they will display well in 80-column email clients even with several levels of quoting.