It’s not that I’m totally opposed to heartbreaking tragedy in a novel. There are three — wait, four — reasons I might pick up a book that’s described as heartbreaking:
a) I have a lot of trust in the book blogger who’s recommending the book.
b) It’s a romance. If it’s a romance, I know it has a happily-ever-after ending, so it’s not likely to be THAT heartbreaking.
c) I’m in the mood for a tragedy. Hey, that happens. About once every other year or so.
d) I TOTALLY trust the author. Elizabeth Wein falls into this category. Not sure who else.
On the other hand, I am totally turned off by horrible screwed up family relationships that the characters struggle against through the entire book on their way to ultimate tragedy. If anything in a book’s description suggests a novel falls into that category, nothing could make me pick it up, no matter how reviews rave about how the writing or the book is “beautiful” or “lyrical” or “ultimately heartwarming” or “raw and honest.”
Book descriptions that hint at that sort of thing are extremely helpful. I just deleted Amazon’s latest “Free for Prime” email about new titles because every single book on the list seemed to fit the category of toxic-family-tragic-ending. (None of them were the titles I linked above, btw. I was just looking for books with certain phrases in the description.)
This is why there’s no point in trying to make a description appeal to every single reader. You can’t. “Heartbreaking” means I will instantly recoil. “Gloomy prose” will make me back away rapidly and really extreme phrases such as “desperate and ultimately futile” means I’ll leap away so hard I wind up practically in the next county. But those types of descriptive phrases must appeal to a subset of readers or they wouldn’t get used. If that’s the subset that will actually enjoy your book, the description is doing its job.