lucy24 - 9:16 pm on Apr 16, 2013 (gmt 0)
why would I want to make more work for myself
The idea here was to make less work for yourself as well as the server. (Yes, both! This is not always the case.) Right now the rules have to test for two different things: location (name of directory) and filetype (extension). If you were setting up new sites, matching up filetypes and directories would save a lot of trouble, because each piece by itself would give your rule the information it needs. /images/ == \.(gif|png|jpg)$ and so on down the list.
If the sites already exist then obviously there's nothing more to do. Unless you've got two domains today but are looking forward to a happy future where you've got a thousand ;) Then it might still be worth the short-term bother of changing things.
And if you make the best possible rules at the beginning, you don't have to go back and fine-tune them later. So it saves aggravation in the long run.