There's no need to depend on gtk-doc to install .html files. See the tracking bug for details.
Following the discussion on the tracking bug, I believe this is NOTABUG
The discussion is not over. As long as the tracking bug stands, this bug stands too.
It is a bug, see:
From the original bug #604169 comment #31
Which by my reading means that all packages which place files in
/usr/share/gtk-doc/ should go ahead and own that dir. (root/root, mode 755).
Committed to master and f14, will be in the next builds