The answers to this question are as numerous as there are readers.
Why are Jane Austen’s novels studied as literature now when they were considered to be merely light entertainment two hundred years ago? Today’s best-written passionate romances are not accepted as literature.
Laurence Sterne’s Tristram Shandy, which begins with the moment of the author’s conception, and equally bawdy Tom Jones by Henry Fielding, are some of the earliest English novels. They include humor at its broadest, but are judged to be literature because of the way they engage with ideas. However today, broad humor is automatically excluded from consideration as literature.
We need to be more thoughtful when we judge literature. Literature can include romance. Literature can include broad humor. Literature is text worth reading because it engages with ideas in original ways. It makes readers pause to reflect. It broadens our thinking.
Having said all that, Aussie Guards has no pretensions towards literature whatsoever. Readers, enjoy yourselves!
A black moment is a lot more than a device for heightening emotions by making the reader sad before everything turns into a triumphant happy ending.
The black moment is the moment of crisis for a character, when all their efforts seem to have failed. It is strongest when the crisis is of their own doing and they cannot blame external circumstances for their predicament. In this moment, the character experiences what their lives will be like after losing the love they have striven for.
The character faces a stark choice—will they sacrifice everything else for love? Has love become more important than their other goals? The black moment proves the thesis of a story, and for a romance, this means proving the supreme importance of love over everything else.
The choice is not easy (it is a BLACK moment) but in a happy-ever-after romance, the sacrifice they make turns out to be the right choice for that character. Without making a sacrifice, the choice is not made and the thesis is not proved. How can a reader be sure the character is genuinely in love if they have skipped to a happy ending without striving for it?
The main difference between a romance and other genres is that both characters have heroic arcs. Both characters need to face black moments, but it is best if the story does not have a double dip into depression, or it will not be a strong story. It is disconcerting to read one character overcoming doubts and then having to plow through the other character having doubts. Characters do not have identical romantic drives or need attention from each other in the same way, so if the romance is well-constructed, the story will show how they can help each other overcome problems despite their own heartache, and earn their happy-ever-after together.