Current situation:

• The community at the English Wikipedia does not want "Add new section" in their encyclopedia articles, as its use will almost always result in articles that do not conform to the local style guide.
• Any editor can add __ NEWSECTIONLINK__ to any Wikipedia article anyway. That results in a functional "Add new section" tab at the top of the page; if that tab gets used, then the result is almost always undesirable (e.g., content sections being added after appendices or navboxes).

Desired situation:

__ NEWSECTIONLINK__ works like __ NOINDEX__ in the mainspace: Even if you type the code into the article, it has no effect at all.