These are not hidden - these are the two primary motivations for using a static site generator. Markdown was invented in order to separate style from content and to make it easier to write. So, the skillset that's required to be able to contribute to the stuff on the website comes down to being able to write.
Maintaining the website is as simple as
You can even edit the website pages directly from Github if you want. You can make changes locally on your laptop and check them out before committing... something you cannot do with a CMS.
Sustainability ? Everything's in a single repo.
Ease of use ? Check out this demo - it's served from this repo and took 15 minutes to make. Try doing that with a CMS...
Now, if we want to add some further info or update a page, you just
- send pull request
- voilà, website is updated.
For now, of course, I've done nothing else but partially reproduce the content that's already on the website, and with a few more minutes, it'll be fully reproduced. However, now you also have the power to easily create new pages, track issues (using github issue tracker) related to the website, etc.
Also, the database is in line-form, so git will handle it efficiently. It's debatable whether it's a good idea to keep that in the website repo, or in it's own repo, but in any case, you can handle the data nicely with Jekyll, by putting it in the
_data directory. See the Jekyll docs on how to work with data.
Now, if the data is in the repo, you can write very simple pages which loop over the data files to to generate pages - see http://jekyllrb.com/docs/templates/...
The best part is that you can build the site slowly as you need new pages or aspects, so you can be very responsive.