Based on your first example, I know what happened and can make an informed decision about whether I need or want to know the details of how it happened. I'd argue that that is not click bait, as it leads with the most important piece of information first. The title could further be improved by writing "Nixon resigned because of XYZ", but that would be nitpicking.

The most beneficial title from the reader's perspective is a title which allows the reader to quickly decide whether they need to know the information and informs the reader with the necessary information as efficiently as possible. Hence the now long dead practice of writing in the form of an inverted pyramid (https://en.wikipedia.org/wiki/Inverted_pyramid_(journalism)).