I have two approaches to romance novels (which does make it a di-lemma - two approaches!).
As a reader, modern popular romances are silly to me. (Then again, they aren't meant to appeal to me.) I like the classic ones: gothic novels, Austen find-the-right-man-with-suitable-tongue-in-cheek stories, the Bronte sisters stories, and so on. I have only a little experience with the genre, garnered from a novel read here by accident, a novel read there because I was looking for a silly escape. Their plots, as you say, are predictable. Variation occurs in the combinations of details. A woman unlucky in love going to a ranch. A woman working in an office going off of a bad breakup finds Him. They're amusing because they're predictable, because they have such awkward euphemisms for emotions and intimacy, because the stereotypes are nigh unbelievable. They're scary because of the things you point out: an independent woman is entrapped into a possibly emotionally abusive and physically intense relationship, made to feel that she can't control herself, and rendered entirely dependent on a man who tumbles precariously between respecting her and being unable to control his desire. Gross.
And yet a second approach interferes. Several years ago, I read some of Janice Radway's work on the readers of popular romance. I think I've recommended it before. It's good, because Radway gives voice to the part of this discussion that too often gets glossed over in the claims that these books suck: the marginalized readers. The readers of these romances are more self-aware than many critics of Harlequin romances and the like give them credit for. Some of the things she noted in a small-group study of readers:
1. They know what to look for, and don't swallow everything that the printers give them, carefully decoding blurbs and trusting the opinions of friends.
2. They often read books they do not really like or fully endorse.
3. Most were married mothers of children.
4. Reading for one reader was a way to escape from the physical and mental exhaustion of taking care of her home, husband, and three children. She eventually obsessed with romance. It built her confidence to the point where, at the urging of her daughter, she worked at a bookstore, networked other readers with a newsletter, and so on.
5. Many of these readers view romances as chronicles of female triumph, a smart and capable heroine who recognizes her qualities and can love her as she wants to be loved. It's marriage or pleasure or love combined with female independence.
6. They're fantasies involving identifying with the main character. Like many fantasies, these narratives do not offer dreams these readers want to come true.
7. Many of them don't see their heroines as typical. Nonreaders of romance see predictable types. They see a variety of individuals.
8. They most like happy endings, the depiction of a growing relationship, and details after the climax of what happens to the characters.
These and other things helped me be less judgmental of both the readers and the genre. Yes, it's heterosexist about pleasure, the reading of male violence as empassioned rather than abusive is highly problematic, and so on. Also, this study wasn't representative then (it was a small group), and the demographics of readers have changed since. Nevertheless, within these systems that attribute legitimacy to women becoming lovers, wives, and mothers, within systems that at once praise independence, look askance at dependent subjects, and make independence seem impossible, romances offer a narrative that allows for temporary satisfaction, solace, or escape to many readers.
In reply to a post lillerina earlier made, these aren't feminist narratives in one way, but they can still do substantial good for their readers.