Did Hardy and Lawrence write romance novels? No. They would have shuddered at the thought. A book that shows people falling in love (or in lust) is not automatically romantic. Hardy's thing was naturalistic determinism, a belief in the inevitability of a harsh fate that drags people down. Nothing romantic about that. And Lawrence's Freudianism is the perfect romance-killer.
Traditional romantic fiction and the modern genre called The Romance Novel aren't the same thing; they're barely kissing cousins. Pamela, the early Gothic romances, Jane Eyre, Sir Walter Scott's works, The Prisoner of Zenda -- as varied as they are, they're all romantic novels. More recently, Tanith Lee's The Silver Metal Lover is an outstanding SF romantic novel. To some, Wuthering Heights is THE quintessential romantic novel (a view I will dispute until my dying day, but that's a different debate).
But the contemporary genre called "romance novel" has almost nothing in common with those books. The genre is strictly formulaic and its sole purpose is to show a woman winning the man of her dreams, and the woman's worth is implicitly measured by the kind of man she attracts (handsome and rich are good). The further implication is that if a woman does not attract a desirable mate, she's somehow a failure as a woman. That's why I have no use for modern romance novels.
Ed Gorman once told me that he'd set out to write at least one novel in every kind of genre fiction there is -- mystery, SF, western, horror, espionage, fantasy, etc. He was going great guns until he ran up against the romance novel, and that one stopped him cold. The guidelines provided by romance publishers were so rigid, so unbending as to what could or could not be included that Ed gave up before he even started.
The genre "romance novel" caters to women who still want to believe "someday my prince will come." It's a very specific niche in the publishing world aimed at a very specifically targeted readership. I do wish we had another term to distinguish this kind of shallow book from other romantic fiction.