Uhhh... just to interject... But that may not always remain the case.
There is a possibility of the title rewrite adding a new input for titles to the edit page. And with the similarities to the section title, it may just end up splitting the setup into two inputs. One for the title/section title and the other for a summary whatever the case. Likely that the auto generated link to the section in the comment will be coded to stay there instead of the current way which allows the user to remove that.

So, ya, that's the current behavior, but remember there is always room for improvement. In fact, adding a proper summary box to the Edit form for sections might be an even better course of action than just saying "The API won't allow custom summaries for sections because you can't do that with the current edit page".
~Daniel Friesen(Dantman) of:
-The Gaiapedia (http://gaia.wikia.com)
-Wikia ACG on Wikia.com (http://wikia.com/wiki/Wikia_ACG)
-and Wiki-Tools.com (http://wiki-tools.com)
Roan Kattouw wrote:
Platonides schreef:
Because it's not possible through the UI and uses an auto-generated edit 
summary. That's what section=new is pretty much about.

Roan Kattouw (Catrope)

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