For code versioning, e.g., in shared development, this creates unnecessarily large diff's. For instances, patches become more difficult to read, because they include lines that haven't actually changed content-wise, just layout-wise.

Well, no.

Here's an example. File a:

    {
        foo         => 'bar',
        hello_world => 'OH HAI',
    }

File a with a long key added, let's call it b:

    {
        foo              => 'bar',
        hello_world      => 'OH HAI',
        longlonglonglong => 1,
    }

Then we do a diff:

    $ diff -uw a b
    --- a	2011-01-06 08:51:55.725595229 -0600
    +++ b	2011-01-06 08:51:52.285595452 -0600
    @@ -1,4 +1,5 @@
     {
         foo         => 'bar',
         hello_world => 'OH HAI',
    +    longlonglonglong => 1,
     }

So see, that's not a problem.