When I work with the CSS editor in Wordpress.com I end up copying and pasting the code back and forth. This because the browser search function doesn't work for me in the field A.F.A.I.K. (It did with an earlier version I.I.R.C.)

Also having such a small field to scroll is really a pain. It is slower than a dedicated program or text processing program.

It is nice to be able to just add CSS changes, when on wordpress.com because it adds quite a lot of functionality en customizing to the appearance of a website.

The put it in Jetpack as plugin option sounds like it could be the better road. This because I do believe core should remain as lean as possible (and this arguably is not user functionality but developer functionality). This is all stuf that will have to be maintained and updated, possibly by a volunteer crew. Which knowing open source will not get any/ little development if not enough people are interested. This could lead to product quality degradation, which could lead to less user, inciting a road to the bottom.

The argument that makes it easier for a user with no experience? I'd rather see a service that people can hire for an affordable price to do small changes. This would also put food on the table of developers. Explaining something like this can take quite a bit of time, and most often the questions I have seen in the forums, the people knew how to make the changes. Some webhosts have easy file manager access, so that's copy and paste, with search functionality.