I don't think it's at all unreasonable to ship with the default document root at /srv/www, which would be empty by default. If you make anything else the document root, many people are just going to edit stuff *there*.
Anyone who wants a different arrangement than the default can edit the document root in httpd.conf, no problem, but there'd be a sensible and standard default already. From the FHS:
Therefore, no program should rely on a specific subdirectory structure of /srv existing or data necessarily being stored in /srv. However /srv should always exist on FHS compliant systems and should be used as the default location for such data.
What I'm suggesting covers both parts of this, not just the first.
Though the current places are also standard for a long time and also covered in many books. Keeping to them and having sysadmins change them to /srv/ might keep FC/RHEL to more conservative setups and stability.
regards,
Florian La Roche