I only just discovered that you can turn off the table of contents (TOC) using a link in the sidebar, when looking at module documentation.
How about making this a checkbox?
Table of Contents: [X]
Or as an alternative, start off with it rolled up by default (you're just wrong, Olaf :-), and display the following at the top of the page, where the full TOC is currently shown by default.
[> Table of Contents
You could click on the arrow to open up the TOC.
That way you can see straight away that there is a TOC, but can then choose whether to see it or not.
No one has come forward to do this, closing as part of the great issue cull of Dec 2013