In reply to colinspColin.

It's true that many CSS changes are theme specific. They're also often specific to the site, regardless of the theme. I've been doing this long enough to see the various use cases. It just depends on what the user needs. Fortunately, plugins can and do handle both scenarios. Themes cannot.

From a user standpoint this may seem "simple", but it's really not. Otherwise, we would've never had multiple discussions on it. There's a lot of complexity to doing this and doing it right. What the new guidelines propose is to merely do it safely. We're not forcing theme authors to do it right.

Also, there is absolutely no difference in "bloat" between a theme doing it and a plugin doing it.

I won't even dive into the implications that such a feature would have on some multisite installs. The theme probably wouldn't be allowed.

The best and recommended method is to simply edit the style.css file (preferably via a child theme). Anyone comfortable enough to add code to their site should be comfortable enough to edit this file.