In emacs, one can take out the drudgery of manually aligning and realigning your variables in tabular fashion using the align commands[1].
In certain revision control systems, one doesn't keep differences, but whole objects, so the point is moot there unless you have some serious bandwidth concerns.
It's not only about bandwidth concerns, it's more about making commit diffs readable. If you have ten lines of tabular assignments and you changed the sixth, but that made you realign everything, then you'll see 10 green lines + 10 pink lines in your commit diff, even though you should only see two lines in total.
In certain revision control systems, one doesn't keep differences, but whole objects, so the point is moot there unless you have some serious bandwidth concerns.
[1] http://www.emacswiki.org/emacs/AlignCommands