I think this policy makes a lot of sense--it's best to ban editorialization of headlines altogether as there's no good objective way for mods to differentiate bad editorialization (sensationalism, inaccuracy) from good editorialization (adding pertinent information, clarifying, and de-sensationalizing).

However, there is also a strong argument to be made that there are good articles with lame titles (such as this one) which would otherwise be glossed over without a title change. Maybe the best solution would be to add a summary field to submissions, restricted to an 80-character, purely factual synopsis of the article's contents. It could show up smaller, beneath the submission headline, like a subtitle.

This way, you gain the benefits of editorialization (providing pertinent info highlighting the article's appeal to HN readers) while minimizing most of the downsides (loss of info provided in the title, misconstruction of the author's intent).