I don't write romance. I READ romance, but I don't write it because I don't find myself focusing on the love interest as a driving plot point. I love including romantic subplots in my books, but I totally understand that's different from writing a romance.
No one is saying that there is no place for tragic romantic stories. No one is saying "don't kill the love interest at the end."
However, as a reader of romance, if I pick up a book in the romance aisle, I have two expectations:
1) The ROMANCE is the primary plot element. Sure, there may be suspense or mystery or adventure or fantasy, but a major plot point is "How will these two crazy kids get together."
2) These two crazy kids WILL GET TOGETHER and be happy at the end of the book.
If you write a story where the romance is secondary to the main plot, or the MCs do NOT end up together for whatever reason (death, disinterest, time displacement, etc.), it is not a romance. By all means, write what you want to write, but MARKET IT appropriately. It's historical fiction, or fantasy, or women's fiction, or mystery or suspense with strong romantic elements.
There is plenty of room on the bookshelves for all types of books. There is no place for snobbery and denigration of certain genres. Anyone who thinks otherwise should really just get over themselves.